Extreme Max 3004.3093 45 degree Base for Slider Trax / OEM Marine Accessory Mounting Systems, Each For Boats with OEM Rails  The multi-fit design fits most boats pre-equipped with gunnel extrusions like Lund & G3. Works great with Lund Sport Trak. Construction  Bases are made of heavy-duty composite for maximum durability and corrosion-free life. OEM Approved  Available pre-installed on certain model boats from recognized OEM leaders. Options  Slider Trax bases and rails are sold separately to maximize ordering options. Warranty  2-year replacement warranty.