Double block with Stainless Steel cheeks and becket. Works with 505-25 or 505-45 for a 4:1 purchase. Delrin(tm) sheaves ensure smooth operation with high safe working load. Swivel head may be locked in place to avoid twist. Sheave Dia. 2″ (51mm), Thickness 1 21/32″ (42mm), Width 2 1/8″ (54mm), Length 6 3/16″ (157mm), SWL 1750 lbs. (795kg), Weight 12.8oz. (363g), Max Line 7/16″ (11mm)