Harken 40mm Triple Carbo Ratchet w/Cam, Becket & 29mm Block features a triple sheave configuration (3 wheels) with a diameter of 40mm each. The ratchet mechanism allows you to hold lines under tension. Integrated into the block, the cam cleat provides a simple way to secure lines by pushing down. This also features a becket which is built into the block for easy and secure attachment to a fixed point on the boat. It also has an additional single sheave with a diameter of 29mm.