Springfield Marine Trac Lock Locking Slide And Swivel 2 7/8in. It is a 7-1/4" x 13" locking seat mounting platform and is constructed of high-strength aluminum to withstand harsh marine environments. This slide and swivel seat mount travels 5-1/4" forward and backward on self-lubricating pads and rotates up to 360 degrees. It adds 1-1/4" of height and can be used with any 2-7/8" fixed height pedestals. Centrally located locking handle is easy to reach with left or right hand. Features of Springfield Marine 1100521-L1 Trac Lock Locking Slide And Swivel 2 7/8in High-strength aluminum construction to withstand harsh marine environments 2-7/8" post mount with bushing for snug fit Large 7-1/4" x 13" seat mounting platform; Travels 5-1/4" forward and backward and rotates 360 Centrally located locking handle is easy to reach with left or right hand Package Contents: Springfield Marine 1100521-L1 Trac Lock Locking Slide And Swivel 2 7/8in Springfield Marine 1100521-L1: Trac Lock Locking Slide And Swivel 2 7/8in