Twin Sheet Block for 1-1/4" T-Track - BlackHardcoat anodized aluminum body and slider provide a high strength block. Aluminum sheave runs on nomex™/Teflon™ bearing for a low-friction, high strength sheave. Articulating sheave allows for a proper lead. Pin stop makes adjustment simple. Specifications:Track Size 1-1/4" x 3/16" (32 mm x 5 mm)Max. Boat Length- 38' (11.5m)Max. Boat Weight- 18000 lbs. (8182kg)Max. Sail Area- 715 sq. ft. (66 m2)Sheave Diameter- 2" (51 mm)Max Line- (2) 5/8" (16 mm)Length- 4-1/2" (114 mm)Width- 1-3/4" (44 mm)Height- 4-1/2" (114 mm)Bearing Height 2-3/4" (70 mm)SWL 3500 lbs. (1590 kg)Weight 1 lb. 7 oz. (652 g)