what is the name of this

[Jeff Birch]

Another name for it is fairlead. It is common term for a variety of devices or fittings that are intended to position or direct lines around an object, out of the way, or to stop it from moving laterally. If you search "fairlead images" on yahoo, you can find other examples.

[Manitoba Mariner]

On the ships I have been on with these they have been called "Rollers" or "Dead man roller"

[Michcrew]

What is the name of this thing. It is part of the aft mooring system and guides the wire from the winch and through the fairlead. It has a roller on top and is connected to the deck. What is its official name? Any help is greatly appreciated.