The B&T Industries Determinator BT62 is a low-tech yet highly effective tool for measuring shot groups within a 1.5-inch diameter. Laser cut from clear acrylic, this device features a glow-in-the-dark cord for easy handling. Simply lay the Determinator over your shot group, adjust until one of the circles crosses the center of the two outermost holes, and read the measurement to determine group size. Ideal for competitive shooters and hunters, the B&T Industries Determinator provides a quick and accurate way to measure shot groups.