GQ GMC300EPlus Fulfill Digital Nuclear Radiation Detector Monitor Meter Radiation detection: Beta, Gamma and X-Ray . Sensitivity to Gamma Radiation: 0.1~1 MeV Own Background: 0,2 Pulses/s Working Voltage: 3.7-5V LCD Display: Dot matrix with back light Working power: 0.045W - 0.2W Power: 3.7V Li-on 14500 rechargeable battery  / USB power