This is a door hinge for Railcore printers meant to prevent the door from swinging open or shut on its own. It uses a simple pin in track mechanism to lock the door open at 0, 90, and 180 degrees. To move the door between positions, simply lift the door slightly from the bottom and swing it to the desired position.

An M3x40mm bolt is required for the center axle. The bottom hole in the door side of the hinge is slightly undersized for M3 – the bolt should be directly threaded into the plastic.