Swivl-Eze is the 1 supplier of 3-4 pin seating hardware Heres why The 3-4 system gives you outstanding economical performance The design is proven by decades of experience Posts are available as fixed, manually adjustable, or power-adjustable Seat mounts, posts and bases available in steel, aluminum, or stainless steel 25 - 31 Hgt., 1.50 Diam., Brushed Alum., Pro-Post, Threaded, Steel Pin California Residents WARNING Cancer and Reproductive Harm - P65Warnings.ca.gov Other Details Google Product