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. Head can be locked at 0 or 90 by engaging the grub screw in either the 0 or 90 degree position. High working load Low maintenance, long service life Sheave Size: 2" (50mm) Line Diameter: 1/2" max. Lockable swiveling head post Slotted pin shackle eliminates fouled lines Grade 316 stainless steel load strap Impact and UV resistant, fiber reinforced Nylon cheeks Self-lubricating Acetal polymer sheave ensures low friction and extreme durability