Ronstan Series 40mm Fiddle Block is perfect for: Mainsheet Halyard Vang Spinnaker control lines on off-the-beach catamarans, one design classes and sportsboats up to 8m (26ft) Ideal for fine-tune mainsheet tackles, cunninghams, backstays and other control line purchase systems. It features: Exceptionally high working loads Low maintenance, long service life Self-lubricating sheave Captive Lock™ universal head Slotted pin shackle eliminates fouled lines Snap fit removable becket pin Multi-position cleat arm Spare parts - RF41010 Replacement Becket Pin, RF150 Shackle Sheave Ø1 9/16 + 15/16 in. Max. Rope Ø5/16 in. Max. Cable Ø- in Pin Ø3/16 in. M.W.L.880 lb. B. L.2200 lb. Weight5.8 oz.