Nikon Spot On Ballistic Wind Meter -The Spot On Wind Meter takes an accurate reading of the wind speed and direction and inputs the data directly into the Spot On Ballistic Match Technology(TM) Application that every serious hunter and shooter should have on their smart phone. Now, the Spot On app not only provides the precise aiming point on your reticle to compensate for distance, but thanks to the new Spot On Wind Meter, you now can also compensate for wind drift. Accurate wind speed, direction, average and gust measurements; Compatible with iPhone, iPad, Ipod, and all major Android devices; Reads in meters/second, miles/hour, and Beaufort scale;