The ring plunger is a piece that secures and locks a bolt that is inserted into the wood to unobtrusively join two pieces. This plunger is placed in a previously opened hole where the bolt is located and then with the Screw for Hitch System, it is assured. It is manufactured with Zamak, a resistant material made of alloys and its finish is zinc plated. The dimensions of this piece consist of 16 mm in diameter by 15.6 mm in total height and 9 mm from the top to the center of the hole through which the bolt must pass. The set screw must be M8x1 and its packaging comes in 1000 units.