Petzl Pirana
The Petzl Pirana offers three braking positions and features two extra friction spurs which allow friction to be varied during descent. There are many different configurations that allow it to be used on various ropes in different conditions. When used with a carabiner that has a cross section of 12mm, it creates a rigid carabiner/descender unit that helps maintain noise discipline. To prevent accidental loss, the Pirana stays attached to the harness during rope insertion which is a useful feature for military and tactical situations where the user may be carrying a lot of other kit. Due to the design, if positioned poorly the risk of leverage on the carabiner gate is still reduced. Rope twisting is prevented because the rope does not go around the device that goes through the carabiner, the carabiner is held in place by the plastic sleeve and so cannot rotate into a weak position.