Swiveled 1.77 seat pedestal adjusts from 16-20 inch inches. It's the perfect seat post for use on fishing, pontoon or curising boats to provide seat elevation. Attwood develops high value, engineered marine products to make life on the water easier to enjoy. Made to meet the demands of boat builders and distribution partners, our products are extensively tested on-site in our lab to provide worry-free boating under all conditions.