Works with all All-Weather and Profile Seat Shells ONLY. Allows them to swivel and easily be removed from the mount disk. The low profile mount will install on any flat surface with (4) screws (Not included). Includes: Mount, adapter plate for the seat bottom, hardware, and the locking flap. Does not work with the Tempress NaviStyle, Elite, Trojan, bench seats, or any other manufacturer’s seat. Base dimensions: 6-11/16″ W x 6-11/16″ L x 1-3/8″ H. Gray.