These are the little turning blocks that are used at the base of the mast to turn the cunningham and outhaul lines back to the 2 cam cleats. These are used on the new boats with the performance line upgrade. These fit the Maffioli Swiftcord we have on our Line page. Sheave dia. (in) 5/8 Length (in) 1-5/32 Weight (oz) 3/8 Max. line dia. (in) 7/32 SWL (lb) 250 Breaking strength (lb) 1200 376Price: $26.40Sale price: $22.95 WE SHIP WORLDWIDE! We charge the actual cost of shipping. You may email us for a shipping cost estimate. Send us email intensitysails(at sign)gmail.com US$10 MINIMUM ORDER