This 2-Pack all-purpose block is a great all around solution. A self-lubricating Acetal polymer sheave ensures low friction and is extremely durable. This block is the right choice for sheets, halyards and control line applications for cruising and racing. The Captive Lock universal head can be fixed in either of two planes, or free to swivel as required.Low maintenance, long service lifeSheave Size: 2" (50mm)Line Diameter: 1/2" max.Grade 316 stainless steel load strap and head fittingImpact and UV resistant, fiber reinforced Nylon cheeks