Structural parts and accessories for vehicles, namely, tow bars for trailers; automobile structural parts and accessories specifically adapted for automobiles, namely, land vehicle couplings, towballs, tow hitches, tow hooks, tow parts, tow structural parts and structural fittings therefor; safety devices for the aforementioned, namely, metal locking devices for trailer hitch couplers, metal locking devices for securing a tow rope to land vehicle couplings, towballs, tow hitches and tow hooks...