Through a combination of geometry, sheave ratios and a unique free-spin bearing, the Synchro range delivers nearly the performance that is achieved by ball and roller bearing blocks used in pro racing, but at a fraction of the price. Wide range - available in singles, doubles, triple, fiddle and snatch blocks Unique free-spin self lubricating bearing Optimized sheave to rope ratio Swivel lock self aligning head Adjustable cams Compatible with ocean pad eyes and upstands Sheave diameter: 2-7/8"