Ronstan Series 25 Utility Block with swivel shackle head. Lightweight durable construction. Economical. Maintenance free. Stainless steel cheeks and Acetal sheaves ensure a long service life with virtually no maintenance. Hollow rivets in the block heads can be fitted with shackles, which can also be used to add a becket for extra purchase. Use for vang, cunningham and trapeze retriever systems on dinghies also for leech line tackles and bunk adjusters etc on smaller yachts. Made from UV stabilised Acetal sheaves and Marine Grade 316 stainless steel cheeks. Dimensions: Sheave ? 25 mm Rope ? 4mm - 6 mm Pin ? 4.0 mm