Petzl Croll

A Petzl Croll is an ascending device used in caving and industrial rope access made by the French company Petzl.

In 1968 Bruno Dressler asked Fernand Petzl, who worked as a metals machinist, to build a rope-ascending tool, today known as the Petzl Croll, that he had developed by adapting the Jumar to pit caving.

For ascent (prusiking or "jugging"), cammed devices (ascenders, Jumar, Petzl Croll) are used that can be pushed up the rope but lock and hold the user's weight when a downward force is applied; these must also be easily removable from the rope without being detached from the user.