Fiddle block with ball bearing delrin(tm) sheaves, becket, adjustable cam cleat. Works with 506-45 for a 4:1 purchase. Delrin(tm) ball bearing sheaves provide low-friction yet high safe working loads. Adjustable cam bracket enables proper cam angle for easy line engagement. Lower Sheave Dia. 2" (51mm), Upper Sheave Dia. 1-7/16" (37mm), Thickness 2 5/16" (58mm), Width 4 1/8" (105mm), Length 7 3/16" (183mm), SWL 1500 lbs. (680kg), Weight 13.6oz (386g), Max Line 7/16" (11mm). NEW Fast Entry Cam Cleat