Attwood Fixed Height Lock'N-Pin Post - Leading the industry in safety this patented system with the Lock' N Pin helps prevent unintentional detachment for seat mounts, posts and bases. These posts are proven in the industry with decades of experience. Lock' N-Pin products exceed ABYC Standard H31.6.1Leads the industry in safetyBrushed AluminumNon-threadedSteel pinDiameter: 1.50in