Seat Mounting Pan attaches to the bottom of the new 2020 Contour Seat and Sport Seat with 4- 6mm x 20mm long bolts. The Seat Mounting Pan at the top is the new one we now sell. It works with the new Sport Seats and Contour Seat. It does not work with the old Bench Seat. The square seat pan at the bottom works only with the old Contour Seat and Bench Seat.