Hello, This is not an Ad, just a 'whizbanger' of an idea that works. Are you stuck with loosie deck and rail fittings and no wife, kids, or even friends to hold that pesky screwdiver on the bolt head while you go below to shunt off the nuts... Then you need the third hand, a highly modified magnetic base assembly available at any machine shop supply, married to various sizes of split collars that can be clamped to the rail, and then have the tool head hold the bolt head, while you... I love it, I want more of it... Sean Herron.