Type W.7175 anemometer. An anemometer is a device used for measuring wind speed, and is also a common weather station instrument. Spherical brass body (dia. 65 mm) with tubular extension containing a rotating inner steel shaft; knurled ring at the base. A flying electrical lead exits from a knurled nut on the side of the sphere, and terminates ion a 2-pin connector. Three cups, each 55 mm in diameter, set at 120 degrees apart and connected to the rotating rod withstraight rods. Fitted in plywood box with NAV1754.