The Lock 'N Pin 3/4" Pin System gives you outstanding economical performance. Designed to prevent unintentional detachment of seat mounts, posts, and bases, Lock 'N Pin components exceed ABYC standards. The 1.5" dia. post is made of brushed aluminum and has a non-threaded steel pin. This complete Lock 'N Pin Kit includes 13" fixed height post, zinc-plated steel seat mount with 3/4" pin, and 7" x 7" base plate.