 In 1958, two Swiss alpinists, Juesi and Marti teamed up, creating the first rope ascender, known as the Jumar.In 1968, Bruno Dressler asked Petzl, who worked as a metals machinist, to build a rope-ascending tool, today known as the Petzl Croll, which he had developed by adapting the Jumar to the specificity of pit caving.Pursuing these developments, in the 1970s Fernand Petzl started a small caving equipment manufacturing company, Petzl.