The innovative design of the Springfield Control Post lets it easily be adjusted for comfortable use as a seat or leaning post. Keep the seat upright for enhanced lower back support or angle it to take the pressure off of your legs. The seat rotates to keep up with your changing casting angles. The corrosion-resistant power rise pedestal has an up/down level for instant height adjustment from 28-1/2" to 35-1/2".Threaded Square Base is made of stainless steel with a satin finish. Below the deck mount requires a 2.5" dia. hole in deck. 7" x 7" with 4" deep cup. | KingPin Threaded Square Steel Base