Double HandedClub Certificate2025
BlåtannNOR 3567
Norges Seilforbund
Sognsveien 73
0854 OSLO
Rated boat velocities in knots
Wind Velocity 4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Beat Angles41.5°41.5°40.1°39.4°39.3°39.4°39.5°40.3°42.6°
Beat VMG2.663.554.134.374.474.514.534.504.28
52°4.045.286.026.326.436.496.546.566.47
60°4.255.506.216.516.636.706.756.806.77
75°4.385.656.356.696.876.977.057.157.18
90°4.275.566.326.736.997.177.307.497.60
110°3.985.356.296.797.127.377.537.807.95
120°3.795.156.146.717.107.427.718.158.49
135°3.314.615.656.406.877.247.598.389.56
150°2.723.914.965.856.496.927.278.019.06
Run VMG2.363.384.305.105.816.366.787.458.17
Gybe Angles146.2°146.2°151.6°155.2°163.3°170.0°177.7°178.1°176.6°
APH ToD:604.2CDL: 7.460APH ToT: 0.9930CertNo:4362
BOAT
ClassX-102 Mk IDesignerNielsJeppesenBuilderNordsø VærftAge date01/1981Series date01/1981Offset fileH099.BOFData file4362
HULL
Length Overall9.990 mMaximum Beam3.346 mDraft1.888 mDisplacement3,846 kgDLR8.2260IMS DivisionCruiser/RacerDynamic Allowance0.030%Age Allowance0.487%
PROPELLER
InstallationShaft exposedTypeFolding 2 bladesDiameter0.380m
CREW
Maximum weight170 kg(default)Minimum weight120 kg ✱ when appliedNon Manual PowerNoCrew Arm Extension
SAIL AREAS (m²)
MeasuredRatedMainsail34.3635.15Headsail Luffed29.5629.56Headsail FlyingSymmetric60.0060.00Asymmetric
STORM SAIL AREAS (m²)
Trysail9.79Storm Jib6.91Heavy Weather Jib18.64
SAIL LIMITS
Headsails5Spinnakers4
STABILITY
Righting MomentN/AStability IndexN/A
The owner and any other person in charge is responsible that boat is complying with her certificate in accordance with RRS 78.1 and ORC Rule 304.
Double HandedClub Certificate2025
BlåtannNOR 3567
Norges Seilforbund
Sognsveien 73
0854 OSLO
Time Allowances in secs/NM
Wind Velocity 4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Beat VMG1351.31014.0872.7822.9805.5798.8794.7800.8840.8
52°891.3681.5598.5570.0559.9554.7550.8548.4556.1
60°847.9654.1579.6552.8542.9537.5533.2529.4531.8
75°821.2637.2567.3538.2523.9516.5510.8503.2501.1
90°842.2647.4569.9535.1515.2502.2493.1481.0473.7
110°905.1673.1572.4529.8505.4488.5478.1461.7452.9
120°949.6698.7586.6536.2507.4485.5466.9441.8423.8
135°1087.6781.8637.1562.3523.9497.2474.0429.4376.4
150°1321.2921.3725.2615.2554.5520.4495.0449.5397.3
Run VMG1527.61063.8836.4705.4620.1566.3530.8483.0440.7
Selected Courses
Windward / Leeward1436.61038.9854.6764.1712.8682.6662.8641.9640.7
All purpose1089.9804.8677.5618.5587.4568.9555.9538.6531.0
Single Number Scoring Options
CourseTime On
Distance
Time On
Time
Windward / Leeward739.00.8120
All purpose604.20.9930
 
Custom scoring options for Australia
Scoring OptionTime On
Distance
Time On
Time
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Custom scoring options for Austria
Scoring OptionTime On
Distance
Time On
Time
Coastal/Long Distance655.20.9158
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Performance Curve4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Coastal/Long Distance1530.71041.4806.7692.5626.9590.3560.3512.3501.5
Custom scoring options for Brazil
Scoring OptionTime On
Time
Upwind "bolina"0.7107
Downwind "popa"0.8739
70% up, 30% down "Ilhabela"0.7529
30% up, 70% down "Ilhabela-inverso"0.8176
Custom scoring options for Bulgaria
Scoring OptionTime On
Distance
Time On
Time
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Predominantly Upwind652.90.9190
Predominantly Downwind607.40.9878
Custom scoring options for Canada
Scoring OptionTODTOT
Triple Number AP Low741.10.8096
Triple Number AP Medium600.70.9988
Triple Number AP High552.71.0857
Triple Number Windward/Leeward Low987.00.6079
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Single Number Predominant Upwind674.90.8891
Single Number Predominant Reaching596.31.0061
Single Number Predominant Downwind633.10.9477
Predominant Upwind - Low864.40.6941
Predominant Upwind - Low/Med694.60.8638
Predominant Upwind - Medium638.40.9398
Predominant Upwind - Med/High612.10.9803
Predominant Upwind - High603.30.9946
Predominant Downwind Low903.80.6638
Predominant Downwind Low/Med681.40.8805
Predominant Downwind Medium588.81.0190
Predominant Downwind Med/High531.61.1286
Predominant Downwind High497.71.2056
Predominant Reaching Low790.60.7589
Predominant Reaching Low/Med625.20.9597
Predominant Reaching Medium563.11.0655
Predominant Reaching Med/High526.81.1390
Predominant Reaching High505.21.1877
SA/DSPL Upwind25.93SA/DSPL Downwind38.27
Scoring OptionTODTOT
5-Band Windward/Leeward Low1093.00.5490
5-Band Windward/Leeward Low/Med828.90.7238
5-Band Windward/Leeward Medium723.90.8288
5-Band Windward/Leeward Med/High666.80.8998
5-Band Windward/Leeward High645.30.9298
Windward/Leeward 60-40 Low1087.00.5520
Windward/Leeward 60-40 Low/Med836.30.7174
Windward/Leeward 60-40 Medium741.50.8092
Windward/Leeward 60-40 Med/High692.90.8659
Windward/Leeward 60-40 High677.60.8855
5-Band AP Low816.00.7353
5-Band AP Low/Med662.10.9062
5-Band AP Medium594.31.0095
5-Band AP Med/High557.81.0756
5-Band AP High540.31.1106
5-Band SF Bay Tour - Low945.40.6346
5-Band SF Bay Tour - Low/Med793.70.7559
5-Band SF Bay Tour - Medium702.60.8540
5-Band SF Bay Tour - Med/High654.60.9166
5-Band SF Bay Tour - High635.50.9442
Chicago-Mac Upwind0.8686
Chicago-Mac All Purpose0.8952
Chicago-Mac Downwind0.9160
Bayview-Mac Cove Island0.6769
Bayview-Mac Shore0.6831
Harvest Moon Regatta525.71.1413
Custom scoring options for Cyprus
Scoring OptionTime On
Distance
Time On
Time
Coastal/Long Distance655.20.9158
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Performance Curve4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Coastal/Long Distance1530.71041.4806.7692.5626.9590.3560.3512.3501.5
Custom scoring options for Denmark
Scoring OptionTime On
Distance
Time On
Time
Coastal/Long Distance655.20.9158
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Performance Curve4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Coastal/Long Distance1530.71041.4806.7692.5626.9590.3560.3512.3501.5
Custom scoring options for Spain
Scoring OptionTime On
Distance
Coastal/Long Distance655.2
Performance Curve4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Coastal/Long Distance1530.71041.4806.7692.5626.9590.3560.3512.3501.5
Custom scoring options for Estonia
Scoring OptionTime On
Distance
Time On
Time
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Custom scoring options for Finland
Scoring OptionTime On
Distance
Time On
Time
FinRating655.20.9158
FinRating, kevyt tuuli1074.30.9309
FinRating, kova tuuli543.70.9197
Custom scoring options for France
Scoring OptionTime On
Distance
Time On
Time
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Custom scoring options for Germany
Scoring OptionTime On
Time
Coastal/Long Distance0.9158
Triple Number Coastal/Long Distance Low0.8096
Triple Number Coastal/Long Distance Medium0.9989
Triple Number Coastal/Long Distance High1.0857
Triple Number Windward/Leeward Low0.6337
Triple Number Windward/Leeward Medium0.8173
Triple Number Windward/Leeward High0.9093
Performance Curve4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Coastal/Long Distance1530.71041.4806.7692.5626.9590.3560.3512.3501.5
For information
General Purpose Handicap (GPH)670.0
Custom scoring options for Greece
Scoring OptionTime On
Distance
Time On
Time
Coastal/Long Distance655.20.9158
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Performance Curve4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Coastal/Long Distance1530.71041.4806.7692.5626.9590.3560.3512.3501.5
Custom scoring options for Hungary
Scoring OptionTime On
Distance
Time On
Time
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Custom scoring options for Israel
Scoring OptionTime On
Distance
Time On
Time
Coastal/Long Distance655.20.9158
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Performance Curve4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Coastal/Long Distance1530.71041.4806.7692.5626.9590.3560.3512.3501.5
Custom scoring options for Japan
Scoring OptionTime On
Distance
Time On
Time
Coastal/Long Distance655.20.9158
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Performance Curve4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Coastal/Long Distance1530.71041.4806.7692.5626.9590.3560.3512.3501.5
Custom scoring options for Korea
Scoring OptionTime On
Distance
Triple Number Coastal/Long Distance Low741.1
Triple Number Coastal/Long Distance Medium600.7
Triple Number Coastal/Long Distance High552.6
Triple Number Windward/Leeward Low946.8
Triple Number Windward/Leeward Medium734.1
Triple Number Windward/Leeward High659.8
Predominantly Upwind652.9
Predominantly Downwind607.4
Predominantly Reaching584.6
Custom scoring options for Lithuania
Scoring OptionTime On
Distance
Time On
Time
Coastal/Long Distance655.20.9158
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Performance Curve4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Coastal/Long Distance1530.71041.4806.7692.5626.9590.3560.3512.3501.5
Custom scoring options for Netherlands
Scoring OptionTime On
Time
Triple Number Coastal/Long Distance Low0.8096
Triple Number Coastal/Long Distance Medium0.9989
Triple Number Coastal/Long Distance High1.0857
Triple Number Windward/Leeward Low0.6337
Triple Number Windward/Leeward Medium0.8173
Triple Number Windward/Leeward High0.9093
Coastal/Long Distance0.9158
Predominantly Upwind0.9190
Predominantly Downwind0.9878
For information
General Purpose Handicap (GPH)670.0
Custom scoring options for Norway
Scoring OptionTime On
Time
Distanseseilas Singeltall  (APH)0.9930
Distanseseilas Trippeltall svak vind0.8096
Distanseseilas Trippeltall mellomvind0.9989
Distanseseilas Trippeltall sterk vind1.0857
Pølsebane Trippeltall svak vind0.6337
Pølsebane Trippeltall mellomvind0.8173
Pølsebane Trippeltall sterk vind0.9093
Motvind Singeltall0.9190
Medvind Singeltall0.9878
Custom scoring options for Portugal
Scoring OptionTime On
Distance
Time On
Time
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Coastal/Long Distance655.20.9158
Custom scoring options for Russia
Scoring OptionTime On
Distance
Time On
Time
Predominantly Upwind652.90.9190
Predominantly Downwind607.40.9878
Custom scoring options for South Africa
Scoring OptionTime On
Distance
Time On
Time
Cape Doctor Inshore641.10.9359
Cape Doctor Coastal533.31.1251
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Custom scoring options for Slovenia
Scoring OptionTime On
Time
Triple Number Coastal/Long Distance Low0.8096
Triple Number Coastal/Long Distance Medium0.9989
Triple Number Coastal/Long Distance High1.0857
Triple Number Windward/Leeward Low0.6337
Triple Number Windward/Leeward Medium0.8173
Triple Number Windward/Leeward High0.9093
Custom scoring options for Switzerland
Scoring OptionTime On
Time
Triple Number Coastal/Long Distance Low0.8096
Triple Number Coastal/Long Distance Medium0.9989
Triple Number Coastal/Long Distance High1.0857
Triple Number Windward/Leeward Low0.6337
Triple Number Windward/Leeward Medium0.8173
Triple Number Windward/Leeward High0.9093
Custom scoring options for Sweden
Scoring OptionTime On
Distance
Time On
Time
Coastal/Long Distance655.20.9158
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Predominantly Upwind652.90.9190
Predominantly Downwind607.40.9878
Performance Curve4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Coastal/Long Distance1530.71041.4806.7692.5626.9590.3560.3512.3501.5
Custom scoring options for Ukraine
Scoring OptionTime On
Distance
Time On
Time
Coastal/Long Distance655.20.9158
Triple Number Coastal/Long Distance Low741.10.8096
Triple Number Coastal/Long Distance Medium600.70.9989
Triple Number Coastal/Long Distance High552.61.0857
Triple Number Windward/Leeward Low946.80.6337
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Performance Curve4 kt 6 kt 8 kt 10 kt 12 kt 14 kt 16 kt 20 kt 24 kt
Coastal/Long Distance1530.71041.4806.7692.5626.9590.3560.3512.3501.5
Custom scoring options for United States of America
Scoring OptionTODTOT
Triple Number AP Low741.10.8096
Triple Number AP Medium600.70.9988
Triple Number AP High552.71.0857
Triple Number Windward/Leeward Low987.00.6079
Triple Number Windward/Leeward Medium734.10.8173
Triple Number Windward/Leeward High659.80.9093
Single Number Predominant Upwind674.90.8891
Single Number Predominant Reaching596.31.0061
Single Number Predominant Downwind633.10.9477
Predominant Upwind - Low864.40.6941
Predominant Upwind - Low/Med694.60.8638
Predominant Upwind - Medium638.40.9398
Predominant Upwind - Med/High612.10.9803
Predominant Upwind - High603.30.9946
Predominant Downwind Low903.80.6638
Predominant Downwind Low/Med681.40.8805
Predominant Downwind Medium588.81.0190
Predominant Downwind Med/High531.61.1286
Predominant Downwind High497.71.2056
Predominant Reaching Low790.60.7589
Predominant Reaching Low/Med625.20.9597
Predominant Reaching Medium563.11.0655
Predominant Reaching Med/High526.81.1390
Predominant Reaching High505.21.1877
SA/DSPL Upwind25.93SA/DSPL Downwind38.27
Scoring OptionTODTOT
5-Band Windward/Leeward Low1093.00.5490
5-Band Windward/Leeward Low/Med828.90.7238
5-Band Windward/Leeward Medium723.90.8288
5-Band Windward/Leeward Med/High666.80.8998
5-Band Windward/Leeward High645.30.9298
Windward/Leeward 60-40 Low1087.00.5520
Windward/Leeward 60-40 Low/Med836.30.7174
Windward/Leeward 60-40 Medium741.50.8092
Windward/Leeward 60-40 Med/High692.90.8659
Windward/Leeward 60-40 High677.60.8855
5-Band AP Low816.00.7353
5-Band AP Low/Med662.10.9062
5-Band AP Medium594.31.0095
5-Band AP Med/High557.81.0756
5-Band AP High540.31.1106
5-Band SF Bay Tour - Low945.40.6346
5-Band SF Bay Tour - Low/Med793.70.7559
5-Band SF Bay Tour - Medium702.60.8540
5-Band SF Bay Tour - Med/High654.60.9166
5-Band SF Bay Tour - High635.50.9442
Chicago-Mac Upwind0.8686
Chicago-Mac All Purpose0.8952
Chicago-Mac Downwind0.9160
Bayview-Mac Cove Island0.6769
Bayview-Mac Shore0.6831
Harvest Moon Regatta525.71.1413
Double HandedClub Certificate2025
BlåtannNOR 3567
Norges Seilforbund
Sognsveien 73
0854 OSLO
Data in meters/kilograms (Metric)
HULL AND APPENDAGES (Lightship Trim)
ClassX-102 Mk IMeasurementHINPlan reviewHull constructionCoredCarbon rudderNoLight stanchionsNoTrim tabNo
LOA9.990Max. Beam3.346Draft1.888Displacement3,846Wetted area19.79IMS L8.047LSM07.761Acc. length9.979Sink (kg/mm) 14.24
VCGD0.000VCGM0.063RM Rated (kg·m) 78.0Limit of positive stability(°) N/AStability IndexN/ADefault crew weight170Declared crew weightN/A
PROPELLER
Propeller TypeFolding 2 blades
InstallationShaft exposedTwin screwNoHydro generatorNo
PRD0.380PBWPIPA0.0057
PSD0.030PHD0.080PHL0.160
PSA16.0°ESL0.670
ST10.030ST20.100ST30.100
ST40.100ST50.100
RIG
Forestay tensionAftInner stayNone FittedMast materialAluminumSingle headsail furlerNoMainsail furlerArticulated bowspritNoNon-circular riggingNoFiber riggingNoAdjustable mast footNoRunning backstays2CheckstaysSpreaders2Rotating mastNo
P12.830IG11.750ISP11.750MDT10.110MDL10.150MDT20.080MDL20.080TL2.780MW0.150GO0.150
E4.360J3.380BAS1.650FSD0.030SFJ0.000SPL3.420WPLTPS0.000BD0.000MWT109.00MCG4.300
Flying Headsail Foretriangles IdISPTPS
FLOTATION AND STABILITY
Calculation methodVCG entered directlyVCG entered0.000Flotation Date01/01/2015
BALLAST
TANKS
INVENTORY
INVENTORY
Fixed Ballast Total0
Total deductible
Total deductible
Double HandedClub Certificate2025
BlåtannNOR 3567
Norges Seilforbund
Sognsveien 73
0854 OSLO
MAINSAIL
IdMHBMUWMTWMHWMQWAreaMeas.DateComment1-2021042613340.221.091.792.883.7134.3626/04/2021FORENKLET
HEADSAIL
IdHHBHUWHTWHHWHQWHLPHLUBtnFlyingFTAreaMeas.DateComment1-2021042613340.000.000.000.000.005.0211.57NoNo 29.5626/04/2021FORENKLET
SYMMETRIC SPINNAKER
IdSLUSLESLSHWSFLAreaMeas.DateComment1-20210426133511.6311.6311.636.200.0060.0026/04/2021FORENKLET
CRUISER/RACER REQUIREMENTS*
Accommodation length10.0 mTable area0.44 m²Headroom1.70 mMinimum number of berths4Personal gear stowage0.16 m³Fresh water capacity80 lMinimum number of seats in cockpit4Food stowage0.24 m³Fuel capacity50 lCabin soleStovesSinksGalley gear stowageToiletWash basinNavigation areaHanging locker
*This list is a summary of the requirements. See IMS Appendix 1 for details.