Single block with lashing eye. Delrin(tm) sheave on plain bearing ensures smooth operation and high safe working load. Sheave Dia. 1 1/16" (27mm), Thickness 19/32 "(15mm), Width 1 3/16" (30mm), Length 2 11/32" (59mm), SWL 900 lbs, Weight 1.5 oz (43g), Max Line 5/16" (8mm)