Attwood Adjustable Lock'N-Pin Post - Thisdesign by Attwood is proven by decades of experience that boaters all over the nation have enjoyed.The Patented Lock' N-Pin system leads the industry in safety. TheLock' N-Pin prevents unintentional detachment for seat mounts, posts and bases. Lock' N-Pin products exceed ABYC Standard H31.6.1Height: 24in-30inDiameter: 1.77inBrushed AluminumNon-threaded steel pin