Rock Exotica Hydra Pulley Helmets The progressive cam works by

The progressive cam works by way of one cam operating inside another cam

In a single device you can now have a frictionless ascent with almost zero sit back and smooth

Pass your climbing line through the small ring then through the big ring

But it goes way beyond just the material

Precision machining and heat treatment make them super-strong

Rock Exotica Hydra Pulley Helmets The progressive cam works byRock Exotica Hydra Pulley The Hydra is a swiveling triple attachment pulley made by Rock Exotica. It combines two devices into one, for a slimmed down option in work positioning, ideal for use on your harness's rope bridge. Also an awesome lanyard adjuster.