CURT E16 5th Wheel Hitch Head Adapter Model 16505CURT E16 5th Wheel Hitch Head Adapter Model 16505 The CURT 5th wheel adapter is designed to allow the CURT E16 5th wheel hitch head to mount on a set of CURT 5th wheel rollers. It easily attaches to the head of your CURT E15 5th wheel hitch and features various mounting holes for simple height adjustment. It can be used with the CURT R16, R20 or R24. This 5th wheel hitch head adapter is constructed from steel and finished with a black carbide powder