Demco 8551011 - Underbed Rail and Installation Kit for Demco Hijacker UMS 5th Wheel and Gooseneck Trailer Hitches Chevy Silverado/Sierra 1500 5'6"’ & 6'6" 2019Custom, underbed rail kit allows for uninhibited use of your truck bed once your hitch is removed. Works with Hijacker Underbed Mount Series (UMS) fifth wheel and gooseneck hitches. No drill frame brackets offer a simple installation. Installation kit is designed for use with Demco Hijacker UMS 5th wheel and gooseneck hitches Underbed rails allow for complete access to truck bed when hitch is removed No exposed rails 4 Mounting holes sit flush with