The Harken 40 mm fixed block is the basic model of the Harken midrange blocks. It comes with a ball bearing sheave for use with 10 mm ropes.Harken low-friction carbo air blocks are lightweight, strong, reliable, and affordable. Companions to the popular Harken Black Magic block line, these small, compact blocks have very high working loads for safe, easy trimming.FeaturesGlass-filled nylon sideplates: load-carrying curved bearing racesIntegral becket allows 2:1 or 3:1 purchaseSpecificationsSheave diameter: 1 9/16″ (40 mm)Length: 2 1/2″ (64 mm)Weight with shackle: 1.4 oz. (40 g)Maximum line diameter: 3/8″ (10 mm)Maximum working load: 485 lb (220 kg)Breaking load: 1620 lb (735 kg)Technical FileInstruction Manual .input-wrapper a { text-decoration: none; / Removes underline / background-color: transparent; / Ensures no background color / } .input-wrapper a:hover { text-decoration: underline; / Adds underline on hover / background-color: transparent !important; / Removes grey highlight / }