RV5: Bolts to standard king pin box. Provides 10" offset for increased maneuverability. Strong machined king pin clamp fastens unit to trailer. Works with manual slider hitches. * Safely converts an RV trailer for towing with a gooseneck ball. * Fits standard king pin box. * Self-latching GNB 25/16" coupler "V-19" 28,000lbs. * 9", 5" or no offset for added maneuverability. * 4" height adjustments in 1" increments (12 1/2"-16 1/2" to top of ball). * Includes coupler release cable and hardware. * 24,000lbs Gross Trailer Weight, 6,000lbs Gross Tongue Weight.