Lewmar 50mm Sync Block Single Black

SYNCHRO BLOCKS
Lewmar Synchro blocks are engineered for speed, efficiency and superior handling. They use a combination of scientifically optimised block geometry, a Free-Spin bearing and self-aligning head to reduce friction and increase efficiency by up to 40% over budget blocks on mainsheet systems. Each component is perfectly synchronised with the movement of the rope, providing you with an easier, smoother transfer of power from deck to sail and less wear on your rope. 
Applications
Plain bearing blocks are typically used for heavy and static loads in:
Halyard tuning
Mainsheet systems
Mast foot blocks
Mast head blocks
Boom vang
Stainless steel strap for improved strength and longer service life
Stiff glass fibre reinforced cheeks to prevent lines from wedging
Innovative design with “tool-free” sliding swivel locking mechanism
Simple switch to change from swivelling to fixed shackle