Series 25 Utility Block(TM) - Single - Loop 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 constructionEconomicalMaintenance freeApplications:Vang, cunningham and trapeze retriever systems on dinghiesLeech line tackles, bunk adjusters, etc on larger boatsMaterials:U.V. stabilized acetal sheavesGrade 316 Stainless Steel cheeksSpecifications:Sheave : 25mm(1)Max. Rope : 6mm(1/4)M.W.L.: 300kg(660lbs)B. L.: 600kg(1,320lbs)Weight: 15g(0.5oz)