Receiver lock provides added security and theft deterrence while towing. 1 in. trailer hitch locking pin is rated up to 3,500 lbs (Class I and II), 5 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 in. (16 mm) Diameter pin fits 2 in. (51 mm) Receiver Tubes, Class III; 1 in. (13 mm) Diameter pin fits 1-1 in. (32 mm) Receiver tubes, Class II; Usable length of each chrome hitch pin lock is 2-3 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 See more product details The Master Lock 2866DAT features 1/2in (13mm) and 5/8in (16mm) Swivel Head receiver locks. The receiver lock includes the Push to Lock locking mechanism, easily used by pushing the lock body firmly onto the pin and removing the key. The Weather Tough seal and water tight cap provides additional protection from moisture and dirt. 4-pin cylinder for added pick resistance