Trailer Hitch Coupler Pin Design:1/4 Inch diameter tongue lock pin with effective length 3/4 Inch. Small size for easy carrying. the coupler lock in your pocket or vehicle anywhere is fine.How To Operate Trailer Tongue Coupler Lock: Spinning the flat key 5-7 to open or the hitch lock.Security Of Coupler Pin: This trailer lock is made of high-strength steel to deter theft. The hitch lock is coated with black electrophoretic paint to prevent corrosion.Coupler Hitch Pin's Application: Tow Trailer Boat RV Truck CarWidely application: provides additional security for your , boat or trailer by securing the coupler on your trailer tongue, also secures trailer door latches, boxes and other types of doors.Colour: black + silverMaterial: iron + alloyPackage Contents:1 * Lock2 * KeyOnly the above package content, other are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.