A few Wenger Swiss Army knives include a snap shackle (also called a carabiner). It allows the user to clip the knife to a belt loop or backpack, to have quicker access to the knife and its tools. Wenger introduced this tool in the 1980's, and was ahead of its time. Knives with carabiners are very popular now, but back then they were rarely seen outside the mountaineering community.
Uses: To attach your Wenger knife to a belt or backpack, just open the snap shackle, and click it over a belt loop or pack strap. There is a lever arm that you can lift, to release the tool.