Trimax 4010216 Tar300 Premium 5/8in Anti-Rattle Ss Key Receiver Lock Machined steel receiver lock with 5/8 inch sleeve O-ring seal and water tight cap help seal out dirt and corrosion Includes wrench Fits class III and IV receivers Easy to install for tight and quiet fit The 5/8" pin fits all Class III, IV and V receiver hitches Receiver pin easily adjusts for a tight fit O-ring keeps water, grime and dirt out of locking mechanism to ensure years of use Protective rubber cap protects keyhole from water, grime and dirt Type A key which is a spring loaded, 7 pin, high security key. Resists attempted drill outs. Rugged and durable, the key will not bend or break.