Fiddle block with anodized aluminum cheeks, cam cleat and becket. Works with 504-45 for a 4:1 purchase. Fast entry cam cleat ensures smooth line engagement. Removable becket allows pre-spliced lines to be easily attached. Delrin(tm) sheaves ensure smooth operation and high safe working load.Sheave Dia. 1-7/16" (37mm), Thickness 2 5/16" (58mm), Width 3 7/32" (82mm), Length 6 13/32" (163mm), SWL 1750 lbs. (795kg), Weight 11.6oz (329g), Max Line 7/16" (11mm)