Constructed of strong steel tubing, the Wise Boat Seat Spider includes a boat seat bracket for easy on and off of any boat seat with a 6" to 7" swivel. Works great with the Flat Swivel (#75631 sold separately). Footprint: 18.25" x 19.25". Height: 12.875" from floor to bottom of the stand. Stand tapers to 8" wide at top.