Swing Speed Radar - EUC [Simple. Reliable. Effective.] The Swing Speed Radar, trusted by athletes for 25 years, delivers accurate swing speed readings at the press of a button. Focus on your swing, not technology. Turn on, swing, see your speed. The Swing Speed Radar keeps it simple, providing all the data you need, instantly and reliably. [No Ball Needed] - Yes, you can use an actual golf ball but there's no need to hit an actual golf ball—use a wiffle ball, Birdie Ball, sponge ball or equivalent to simulate a real ball. Immediate feedback provides a basis for golfers to determine swing improvements [Speed Measurement] - Range of speed measurement from 20 MPH to over 200 MPH. Speed drives more distance. For every 1 mph gain an average of 1 to 2 yards distance is gained. [Works With Most Swing Speed Trainers] - Works with the Stack System, RypStick, SuperSpeed Stick and other popular swing trainers. Combine this with a trainer, clubs and irons to increase speed and get more yards. It may be necessary to elevate the Swing Speed Radar up to 8 inches off the ground as the use of swing trainers tends to shorten the viewing plane of the doppler radar. The swing plane of the base of the swing trainer must be level with the Swing Speed Radar to produce accurate results. Powered by 3 AA batteries [Doppler Radar Technology] - This Swing Speed Radar utilizes Doppler radar technology to measure swing speed. Item dimensions L x W x H 3.75 x 2 x 5.5 inches Screen Size 5.5 Inches