The GRI 2120 Ribbed Switch, designed to complete a multi-task role, is a unique combination of special features and materials. The unusual ribbed outside diameter permits a secure mounting over a wide range of drilled hole sizes. The installer does not have to glue this recessed switch into a slightly oversized hole, as the flexible ribs conform as it is pressed into the wood. Self adjusting to fit the larger hole, the 2120 also centers itself to the coverage of the misdrilled hole. Picked especially for the 2120 Ribbed Switches, a new material with enhanced memory properties allows the ribbed "O" rings to flex enough to fit an undersized hole but still maintain a firm holding force in an over-sized hole. This mix of features yields an additional bonus in that it provides a high degree of protection from crushing, such as that encountered when wood swells or headers shift.