A through deck bush, also known as a fairlead, is designed to protect a surface from a rubbing rope or wire, they can also be used to act as a deflecting point.
In most applications, a through deck bush is used to guide a rope through a surface, such as the thwart or strut of a boat. It also offers protection to the material the rope or wire is passing through.
Allen offers a wide range of through deck bushes in many different materials and shapes. One of their most popular ranges is the aluminum threaded through deck bush. The two bushes simply screw together either side of a surface resulting in a neat finish on both sides, as well as, offering more protection if the rope or wire is deflecting either side.
These are available in six colors which gives the option of having color coded control systems or simply giving a touch of personal flavor. See the complete range of Allen through deck bushes here.