This is a remote control for a cable-actuated dropper post on a mountain bike. There are two parts -- a handlebar clamp that slides on over the end of the handlebar and is clamped in place with a bolt and nut, and a "trigger" that is attached to the clamp -- I used a piece of plastic tubing for the "axle" of the trigger, but a screw would work too.

This remote is designed to be pretty robust, but could get damaged in a crash (like any bike part), but at least you can just print a new one!