Lewmar synchro blocks are engineered for speed, efficiency and superior
handling. Lewmar uses 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 part is perfectly synchronized with the movement of the
ropes, providing you with an easier, smoother transfer of power from
deck to sail and less wear on your rope.