M100-05 Single Block. Computer machined block finished in hardcoat anodized black for durability. Torlon(tm) rollers and Delrin(tm) ball bearings ensure a low-friction aluminum sheave that will handle high loads. Machined center of the block may be used as a " becket" eliminating the need for other blocks. Forged 17-4 D Shackle on a swivel head may be locked in place to eliminate line twist. Flushing holes in each cheek allow easy flushing. Safe Working Load 7500 lbs (3410kg), Weight 25.0oz(707gm), Max. Line 3/4"(19mm), Sheave Diameter 4" (100mm), Shackle 3/8" Pin (10mm), Length 7.7" (196mm), Width 4" (100mm).