This all-purpose blockis a great all around solution. A self-lubricating Acetal polymer sheaveensures low friction and is extremely durable.This blockis the right choice for sheets, halyards and control line applications for cruising and racing. High working load Low maintenance, long service life Sheave Size: 2" (50mm) Line Diameter: 1/2" max. Grade 316 stainless steel load strap Impact and UV resistant, fiber reinforced Nylon cheeks