2 pack, 5/8", 16 mm, class iii/iv, barbell pin receiver lock, keyed alike, includes the push to lock locking mechanism, easily used by pushing the lock body firmly onto the pin & removing the key, weather tough seal & water tight cap provides additional protection from moisture & dirt, fits 5/8", 16mm receivers, usable length of receiver pin is 23/4", 70 mm, 10,000 lb load rating, 4 pin cylinder for added pick resistance, uses master lock key blank k1box or ilco blank m1 TV# 320952, not included.