10 Series Fiddle Block with Stainless Steel cheeks and Aluminum "universal circuit" ball bearing sheaves. Works with 10-55-uc for a powerful 4:1 system. Aluminum sheaves run on Delrin(tm) ball bearings for a very strong yet low-friction sheave. Unique single top sheave and two in-line sheaves spread the load reducing friction and chafe. Stainless Steel D shackle run on a swivel head that may be locked in plate to avoid line twist. Bolted construction allows for easy maintainence. Sheave Dia. 3 1/4" (83mm), Lower Sheaves dia. 2-3/8" (60mm), Thickness 1-7/32" (31mm), Width 4-13/16" (122mm), Length 9-1/4" (235mm), SWL 3750 lbs (1750kg), Weight 3lbs 1oz (1.39kg), Max Line 5/8" (16mm)