Fiddle block with anodized aluminum cheeks. Works with 704-75 for a 4:1 purchase. Delrin(tm) sheaves feature a single top sheave and two in-line sheaves to spread the load reducing friction and chafe. Swivel head design may be locked in place to avoid twist. Upper Sheave Dia. 2 3/8" (60mm), Lower sheaves diameter 1-13/16" (46mm) Thickness 1 3/32" (28mm), Width 3 31/32" (101mm), Length 7 15/32" (190mm), SWL 2250 lbs. (1020kg), Weight 14.3oz(405g), Max Line 1/2" (13mm)