Through a combination of geometry, sheave ratios and a unique free spin bearing, Lewmar's Synchro range delivers nearly the performace that is achieved by ball and roller bearing blocks used in pro racing. Fits Synchro snap shackle Optimized sheave to rope ratio Swivel lock self aligning head Adjustable cams Compatible with ocean pad eyes and upstands Sheave diameter: 2" Sheave SWL: 990 lbs.