This portable dose alarm features a high-sensitivity GM sensor (geiger counter) and advanced chip and is suitable for detecting X-ray, gm and hard . Dual display of equivalent dose rate (DER): current and cumulative. And the dual alarm values can be preset, with sound, vibration or light alarm method to choose from. 128*64 resolution, clear digital display with backlight, easy to read even in dark environments; Chinese/English switchable, with power-off memory function. Powered by 2 AAA batteries (not included), with low voltage indicator. Control buttons for easy operation, 3 detection units switchable (Sv/h, Gy/h, mR/h). Compact and lightweight, convenient to carry. It can be widely used in radioactive environments, factories, high altitude environments, ionising/nuclear radiation, steel/mineral/stone detection, iodine 131 detection and so on. Features: 128 x 64 resolution, clear digital display for easy reading, Chinese/English switchable, with power off memory function. Powered by 2 AAA batteries (not included), with low voltage indicator. Control buttons for easy operation, 3 detection units switchable (Sv/h, Gy/h, mR/h). Compact and lightweight, convenient to carry. It can be widely used in medical environments, factories, altitudes / ionising / nuclear radiation environments, steel/mineral/stone detection, iodine 131 detection and so on. Note:Size and color may be slightly different due to manual measurement and different light environment. Thank you for your understanding. Specifications: Colour: black. Material: ABS Resolution: 128*64 Radiation detection: X-ray, -rays, hard rays Energy range: 50 keV ~ 1.5 MeV 30% (for 137 Cs-) Normal quantity: within 0.5 sv/h. Relative self-error: 8% (137CS1mSv/h) Detector: Energy Compensation GM Tube (Geiger Counter) Sensitivity: 80 CPM/Sv/h (for Co-60) Unit: Sv/h, Gy/h, mR/h. Measuring range: - Equivalent dose rate (DER): 0.08 ~ 1000 Sv/h (max. 10 mSv/h). --Cumulative equivalent dose rate: 0.00 Sv ~ 500.0 mSV Alarm setting: - Equivalent dose rate (DER): choose from 0.5, 1.0, 2.0, 2.5, 5.0, 10.0, 50.0, 100.0 Sv/h --Cumulative dosage equivalent rate: choose from 0.05, 0.5, 1.0, 2.0, 5.0, 10.0, 20.0, 50.0, 100.0 sSV Operating environment: -10~45C, 95% RH (45C). Power supply: 2 x AAA battery (not included) Item Size: 102 * 69 * 26 mm / 4.02 * 2.72 * 1.02 inch Package contents: 1 x dose alarm.