The BOLT Locks Fifth Wheel King Pin Locking System features a U-shaped, black powdercoated, hardened steel collar that wraps around the fifth wheel king pin and attaches to a BOLT 5/8” Receiver Lock to securely hold the fifth wheel in place in the bed of the pickup. The company's 5/8” Receiver Lock is a stainless steel pin featuring a double ball bearing locking mechanism with a weather-resistant lock shutter to keep out dirt and moisture. Once the vehicle ignition key is inserted into the lock cylinder, spring-loaded plate tumblers move up and down until they are matched exactly to that key. The first time the key is rotated, the cylinder is uniquely coded to that key.