Master King Pin Lock - Toy Hauler/Trailer Locks w/ BumpStop #387NKA Solid, cast aluminum alloy withstands physical attacks. Lock, protected by the housing, resists common physical attacks: 1) Shackle cannot be cut. 2) Hardened steel bottom plate resists drill attacks. 3) Rivets are countersunk making chisel attempts fruitless Bright red finish and red flag are visible to the driver from a distance. Handle makes it easy to carry. Available Keyed Alike for your entire fleet.