... accessories.General Specs: Transmission distance > 100 metersTransmission angle 360 degreesPower required2 AAA 1.5 voltBattery life1-2 years with ... matrix LCD display120 character inputTransmission distance, >100 metersTransmission angle:360 degreesDimensions of handset,52.8mm * 14.5mm*116mmPower, two ... , Personal Response Systems or Clickers. Support 2000users and 360 degree Wireless Voting Systems