In the auto mode of the ratchet mechanism engages when load is applied, but switches off when it's released. This lets the sheet run out smoothly and freely-great for rapid easing of the sheet and for gybing asymmetric spinnakers.
The sophisticated NC-machined sheave features Generation 2 of Ronstan's patented sheave cross-hole geometry. Its holding power is up to 21:1. The unique sheave design has 12 gripping faces which directly resist loaded line movement. Traditional designes have only 8 faces with an angled resistance to line movement. These faces are offset from the radial line, to draw the rope down into the gripping area when under load.