Called the world's smallest radar gun, the Pocket Radar Hand-Held Gun packs a ton of features into a very small package. Its size, weight and accuracy are designed to get players, coaches and fans in on the action. Using a Doppler speed radar system, speed is detected by a small pulse of radio waves. This can measure how fast an object is traveling either towards or away from the gun. A recall button allows the user to view the last ten readings taken by the gun. This model can measure anywhere from 7 MPH to 375 MPH, with measurements available in both MPH and KPH. It is accurate within +/- 1 MPH. Its Instant-On feature allows the devide to power up and take a speed measurement in less than 1 second. Measuring in at just 4.7" x 2.3" x 0.8" and weighing only 3.7 ounces, you might be surprised to find out that this gun can take more than 10,000 readings on just 2 "AAA" alkaline batteries. Easy to use, one-button “Point and Shoot” interface.