Working-Model-Anemometer-RVFM-B19001-Anemometers-are-used-to-measure-wind-velocity-This-working-model-consists-of-four-moulded-plastic-cups-supported-by-four-arms-The-arms-are-mounted-on-a-low-friction-pivot-so-that-even-a-gentle-breeze-will-start-the-cups-moving-By-counting-the-number-of-revolutions-as-indicated-by-the-red-cup-an-estimate-of-the-wind-speed-can-be-obtained-Anemometer-Working-Model