This 5th wheel wedge is designed to fit the CURT E16 5th wheel and accommodates the Sidewinder pin box. It comes with all necessary hardware and features a durable carbide finish for rust-resistance. A 5th wheel wedge is a simple but reliable way to allow a CURT 5th wheel hitch to be used with a 5th wheel pin box. A pin box mounts on top of the 5th wheel head and provides a new pivot point for the kingpin and wider turn radius for the 5th wheel trailer. To keep the pin box from swiveling in its 5th wheel mounting location, a 5th wheel wedge inserts into the hitch head, locking the pin box into place. Sidewinder is a trademark of Cequent Consumer Products Permanently attaches behind the kingpin of the pin box Protected by a highly durable carbide powder coat finish Made in USA | Curt E16 5th Wheel Wedge