The Springfield Boat Seat Pedestal features air-powered height adjustment from 14 to 20 inches. Springfield Marine knows that comfort is important in marine seating. Whether behind the wheel for long passages in rough water, dropping a line in a quiet creek, or anywhere in between. Springfield Marine offers a wide range of configurations and options.• Type: Adjustable Height• Adjustable Height: 14-1/2 Inch To 20-1/2 Inch• Post Diameter: 2-3/8 Inch• Finish: Anodized• Color: Silver• Material: Aluminum• ABYC Code: H-31 AD• With Seat Mount: Yes 2-3/8 Inch Post Diameter Anodized; Aluminum With Seat Mount And Slider, 9 Inch Pedestal Base | Boat Seat Pedestal, 2-3/8" Pedestal with 9" Round Base