Provides accurate measurement of relative wind speed and direction. When combined with other sensors like boat speed and compass, the masthead transducer provides the necessary wind information to calculate true wind speed, true direction and many other advanced data items. The 300mm short-arm version is the perfect choice for cruising sailboats or power boats. High performance sailing boats may prefer the 600mm long-arm version which moves the transducer farther away from the updraft of the boat's sails for enhanced accuracy. Durable anodized aluminum and UV-stabilized plastic constructionMasthead mounting block and interconnect cable includedCompatible with i60 Wind, iTC-5, ST60+ and ST60 series instruments