The Springfield Seat Mount Suspension System measures 7"W x 8-1/2"L x 2-1/2"H. It's made of high-strength aluminum with heavy-duty 515 springs that provide a comfortable ride. 5-yr. mfr. warranty. *The Springfield Seat Suspension System is only rated ABYC Class B, designed for occupancy at boat speeds not exceeding 5 MPH. Ideal for fishing or trolling. Measures 7""W x 8-1/2""L x 2-1/2""H | Springfield Marine Seat Mount Suspension System