Single block with anodized aluminum cheeks. Delrin(tm) sheave ensures smooth operation with high safe working load. Swivel head may be locked in place to avoid twist. Sheave Dia. 2" (51mm), Thickness 15/16" (24mm), Width 2 1/8" (54mm), Length 4 13/32" (112mm), SWL 1750 lbs. (795kg), Weight 5oz. (142g), Max Line size 7/16" (11mm)