Lazy Jacks contain mainsails while reefing and dousing. They work extremely well with full-batten mains, but can also be used with conventional sails.FEATURES:Boat length (m): 6.4 - 8.5 mBoat length (ft): 21 - 28 ftBoom length (m): 2.13 - 3.96 mBoom length (ft): 7 - 13 ftMainsail luff length (m): 6.4 - 9.75 mMainsail luff length (ft): 21 - 32 ft