Series 25 Utility Block - Single - Swivel Shackle HeadStainless 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. Features: Lightweight durable construction Economical Maintenance free Applications: Vang, cunningham and trapeze retriever systems on dinghies Leech line tackles, bunk adjusters, etc on larger boats Materials: U.V. stabilized acetal sheaves Grade 316 Stainless Steel cheeks Specifications:Sheave :t25mm(1")Max. Rope : 6mm(1/4")Pin : 4mm(5/32")M.W.L.:t150kg(330lbs)B. L.:t300kg(660lbs)Weight:t20g(0.7oz)