This spring-loaded support locks a shelf securely in place. It has a nickel-plated zinc alloy pin sized to fit 5mm diameter holes, with a tip rounded and polished to slide into place without scratching the wall of the cabinet. Designed to install in a shelf at least 18mm thick.
To move the shelf, use a small screwdriver in the access channel on the underside of the support to draw the pin back; it will lock in the retracted position. Sold in packages of 20.