Microwave Doppler radar unit that attaches to the back of a baseball glove
A small Doppler radar velocity sensor which attaches to a baseball or softball glove, the Sports Sensors Glove Radar measures the speed of a ball just before it is caught. By learning the proper way to condition, train, warm-up, and throw, players can achieve their best accuracy and velocity performance, while reducing the risks of injury to their arm and body. It can aid any player--infielders and outfielders, as well as pitchers and catchers--throwing from any distance.

The Glove Radar attaches easily to the back of any glove. Packaged in a rugged plastic housing assembly and sealed to protect the internal electronics from dust, dirt and moisture, the Glove Radar is worn by the receiver of the ball, or by multiple tossing partners in non-game situations. It then responds to the approaching ball just before it reaches the glove. Thus, unlike most radar speed guns, a long range capability is not required.
Two screws hold the cover in place, which can be removed to replace the internal battery. A strong, weather-resistant nylon cord, facilitates attachment to virtually any ball glove. A rubber pad, molded onto the housing surface adjacent to the glove, absorbs impact shock forces from the ball being caught.
The internal electronics are in "sleep" mode until activated by depressing the push-button On switch. Upon receipt of a velocity signal produced by a ball about to be caught in the glove, the ball speed is calculated and shown on the display in miles-per-hour. The Glove Radar goes into the sleep mode after an inactivity period of about a minute. It's backed by a 6-month limited warranty. Made in USA.
Specifications:
Size: Triangular shape, 2-1/2 x 3-1/2 x 1-3/16 inches
Weight: 3 ounces
Attachment: 40 inch, 1/8-inch diameter, weather-resistant, durable nylon cord
Display Type: 2-1/2 Segment LCD
Speed Units: Miles-Per-Hour (MPH)
Speed Range: 20 to 120 MPH
Accuracy: Within 1 MPH of typical sports radar speed guns located at comparable receiving positions
Battery: 3 Volt, 160 mAh, Lithium CR-1/3N, DL-1/3N, 2L76BP
Battery Operating Life: Over 30 hours of continuous use; over 5000 transmission cycles (5000 speed measurements)