The one variable that most greatly affects your precision rifle accuracy is the one over which you have the least control - the wind. Now, take charge of the wind with the Caldwell Vector Wind Flag. You'll be amazed how those 1 1/2" groups turn into 1/2" groups. Features Include: Lightweight, sensitive and durable for making accurate wind assessments, Directional Vanes, Pinwheel and Tail Flags give you quick visual cues for the most minor wind changes, Use 3 flags to read relative wind speeds and direction, at ranges of 20, 40 and 70 yards. Knowing both the direction of the wind and the relative wind velocity can put those unexplained "flyers" back in their place: the bullseye.