JENDYK Universal Air Brake Truck Locks Are Used For Almost All Truck Locks to Reduce Theft. JENDYK Universal Air Brake Truck Locks are made of cast aluminum to provide long lasting durability. Used by drivers, truck dealers, repair shops, mechanics, fleets and more to secure trucks on the road or in truck yards. The air brake lock is designed to fit almost all truck locks, including those with curved dash boards and oversized knobs. Reduces risk of theft when on the road or in the truck yard. Available types are Keyed Alike, Keyed Differently and Keyed Differently w/Master Key. Styles are Double Knob or Single Knob.Lengths are 3-1/2" or 5-1/2". Other dimensions vary per style.