Product Description Ronstan Series 75 Ratchet & Ball Bearing Blocks 3:1 Coarse & 6:1 Fine Rope Not IncludedFeatures Coarse and and fine tuning purchase system Unrivaled 18:1 holding power Dual sided On-Off switch Low friction ball bearing system Lightweight Cheek cut-outs for easy bearing maintenance Sheave Ø - 3 + 2 in. Max. Rope Ø - 3/8 in. Max. Cable Ø - in Pin Ø - in. M.W.L. - 1760 lb. B. L. - 3750 lb. Weight - 49.9 oz.Product InformationTwo-speed mainsheet systems allow both coarse and fine tuning in a single purchase system. The system allows fine tuning of the mainsheet when sailing upwind by using one of the sheet tails and keeping the other cleated. Using both the sheets at once allows the trimmer to blow off the main quickly when rounding the top mark and trim on quickly when hardening up after rounding the bottom mark. When fitting to traveler cars, ensure adequate support for the bottom block and use stand-up spring kit RF324-1 or RF324-2. (Refer to traveler section for more information).Applications Mainsheets on sportsboats and keel boats to 12m (40ft) Mainsheets on sportsboats and keelboats to 12m (40') Max. mainsail area, END boom sheeting = 38sq m (409 sq ft) Max. mainsail area, MID boom sheeting = 23sq m (248 sq ft)Materials Carbon Black Acetal ball bearings U.V. stabilized Acetal sheaves, alloy ratchet sheaves Alloy cheeks Torlon® ratchet pawl Adjustable cleat arms
