The Heininger Advantage SportsRack 2 in. Trailer Hitch Lock is great for securing your bike rack or trailer to the hitch. It has a 5/8 in. diameter and fits 2 in. x 2 in. trailer hitches (Class III and Class IV). It’s inside width is 2-5/8 in. and has an overall length of 6 in.. The weather-resistant lock features a covered key opening for added durability. It also comes with two keys for your safety and convenience. Use in place of standard pin and clip to prevent drawbar or accessory (bike rack/cargo carrier) theft. Made in the USA.