This single block is ideal for high-load applications. Wear-resistant Nylatron® sheave material in lightweight, self-lubricating polymer is suitable for use with rope or wire. Grade 316 stainless steel load strap and head fitting. Impact- and UV-resistant, fiber reinforced nylon cheeks. Use for halyards, backstay tackle, vang components or spinnaker control lines on off-the-beach catamarans, one-design classes or sportboats up to 26'.