Molded to fit the specific shape of your 2 5/16 inches trailer coupler or gooseneck trailer (Atwood attachment) when unhitched; Materials used by AMPLOCK provide good corrosion resistance for use in all climates; Easy to use with AMPLOCK’s push and lock system; The strongest lock to secure your trailer made with high quality materials and control and identification key system; Protect your trailer worry-free with the best trailer coupler lock on market