Half-Moon base block. UC Aluminum sheave features Nomex(tm)/Teflon(tm) bearing with delrin(tm) ball bearings for a low-friction high strength sheave. Heavy Duty Stainless Steel cage includes a flare on each side for a low-friction lead into the block. Sheave Dia. 2-3/8" (60 mm), Max Line 5/8" (16mm), Length 3-5/16"(100mm), Width 1-5/8" (41mm), Height 3-5/32" (80mm), Bearing Height 25/32" (20mm) Fasterners (2) 1/4" RH (6mm), C/C 3" (76mm), SWL 3000 lbs. (1361 kg), Weight 11.3 oz (320g)