The Kestrel with Hornady 4DOF Weather Meter quickly and accurately determines long range holdovers and windage corrections to get you on target with first round hits. This all-in-one unit combines real-time environmental measurements with the 4DOF ballistics calculator for a rugged and dependable, compact yet powerful long-range shooting tool. No more DOPE cards, guessing at the wind, or being unsure where your bullet will hit when you change elevation.