The Supertool was Leatherman’s third production design, and the first to feature locking tools. Based on the by then very successful PST in 1994, the Supertool is essentially a PST on steroids….
It proved to be a real hit with professionals and although not manufactured since 2001, the Supertool is still very highly regarded by multitool users, and examples in good condition are becoming harder to find. The tool locking mechanism required adjacent tools to be opened in order to release them. Primitive, but very effective and strong, whilst avoiding the need for complicated extra components and potential failure.
Having been in production for 17 years in total, the Supertool experienced many subtle modifications. In the picture below, you can see three distinctly different blade patterns, starting with the original “sabre” clip-point design in the earliest example (top) and the much less pointed clip point on the latest example (the middle, Black Oxide).
In essence however, the Supertool stayed pretty much the same and remained in production until 2001, when it was replaced by the Supertool 200.
multitool.org’s multitool encyclopedia has extensive information about the Supertool.