Protect your property by keeping it locked with the TRA3 receiver lock. The patented TRA3 receiver lock is backed by a lifetime warranty and features a solid steel, dual-locking design and a watertight cap. This unique design prevents false locking so the lock will not simply pop open unexpectedly. The locking mechanism functions in 1/4-turns and comes with tubular keys that are not prone to bending or breaking like flat models. Right-angle orientation is ideal for hitches that have close interference on the sides. 5/8" diameter.