Raymarine is what used to be Autohelm - the ST50 range had Autohelm printed on them - so the windspeed and director is a wind instrument - well thats what it sounds like.
It could be a description of the attachment for an autohelm which allows it to be steered by wind direction rather than from the fluxgate compass. I have one. It is a simple vane, mounted on a short mast with a wandering lead that plugs into the control box. I have not used it so cannot comment on its effectivenss.