Master Lock Trailer Hitch Lock, Fits 1-7/8 in., 2 in., and Most 2-5/16 in. Trailer Couplers, Weather Resistant Automotive Hitch Lock with Keys, 377KA;

The Master Lock 377KA Trailer Hitch Lock features a trailer coupler lock, designed to fit 1-7/8 in. (48mm), 2 in. (51mm) and most 2-5/16 in. (59mm) trailer couplers. The advanced locking mechanism provides resistance to picking and prying. The Limited Lifetime Warranty provides peace of mind from a brand you know and can trust.