12 Series Fiddle Block with UC Ball bearing sheaves. Powerful aluminum sheaves run on Nomex(tm)/Teflon(tm) composite bearing and twin ball bearing races for maximum thrust load capacity. Works with 120-55-UC for a powerful 4:1 system. Stainless Steel cheeks are reinforced for high loads. Swivel head "D" Shackle may be locked in place. Bolted construction allows for disassembly and proper maintainence. Sheave Dia. 4" (102mm), Thickness 1 1/2" (38mm), Width 4" (102mm), Length 11 9/32" (286mm), SWL 5000 lbs (2270kg), Weight 4lbs 1oz (1.84kg), Max Line 3/4" (19mm)