Heininger HitchMate (6036) 1-1/8" Trailer Coupler Latch Lock Pin diameter is 1/4 inch, inside width 1-1/8 inch and overall length is 4.75 inch Double nickel chrome finish lock housing Patented, pickproof screw and lock security; 5-pin tumbler and 2 keys included Designed to fit the popular RAM couplers Made in USA