Receiver lock provides added security and theft deterrence while towing 1/2 in. trailer hitch locking pin is rated up to 3,500 lbs (Class I and II), 5/8 in. trailer hitch locking pin is rated up to 10,000 lbs (Class III and IV) Locking head rotates 360 degrees allowing keyway to conveniently face forward; receiver lock features push-to-lock locking mechanism to ensure a secure lock every time; Push head firmly onto the pin and remove key Snap-on cover provides weather resistance and prevents dirt and moisture from entering keyway, four-pin cylinder for added security to prevent lock picking 5/8 in. (16 mm) Diameter pin fits 2 in. (51 mm) Receiver Tubes, Class III/IV; 1/2 in. (13 mm) Diameter pin fits 1-1/4 in. (32 mm) Receiver tubes, Class II; Usable length of each chrome hitch pin lock is 2-3/4 in. (70 mm) Included Components: Two Pins, Two Keys, One Locking Swivel Head For compatibility with bike or other storage racks, please consult the rack manufacturer’s recommendations prior to using this product