Viking Vault Mfg. Ironclad Trailer Hitch Security-  Coupler and Mount Bolt Combo.  Made in the USA 1/8" All welded steel. Bolt Cutter Proof. (2) Master Lock- Puck with 4 keys Orange Finish Will fit 2 5/16" Big Tex/ Demco EZ Coupler. The only way to open this system is with the key. Only power tools or a cutting torch have any chance against this lock. Coupler/Hitch not included.