Springfield 1080136 2-7/8-Inch EZ-Ride Wave Dampening Pedestal ABYC Class: AD (H-31 Driver) 2-7/8 Cast Aluminum Pedestal With 9 Round Base Provides Standard Mounting Pedestal Style Shock Absorbing With Shock Absorbent Mechanical Spring Accepts Any Springfield Marine Post Mount Seat Swivel Or Slide & Swivel 5-year warranty