Features:  Portable Radiation Tester -- This portable dose alarm adopts high sensitivity GM sensor (Geiger Counter) and advanced chip, it's suitable for detecting X, γ and Hard β rays. Dual display of Dose Equivalent Rate (DER): real-time and 5-minute average values.  LCD Backlight Screen -- Clear LCD digital display with backlight, clear at a glance, easy to read even in dark environments; Chinese/ English interface switchable; automatic data storage upon power cutoff, more humanized to use.  Rechargeable Battery, Low Voltage Indication -- Built in with 2 lithium batteries, 2400mAh high capacity and low power consumption ensure strong endurance. Easy to remove the batteries and charge them through the USB interface after removing the protective cap. With battery under-voltage indication function.  Easy Operation, Alarm Function -- Control buttons bring easy operation, 3 detecting units switchable (μSv/h, μGy/h, mR/h). The DER alarm value can be preset among 9 selections. When reaching the alarm value, there will be a sound alarm. Compact and lightweight, convenient to carry with you.  Wide Application -- It can be widely used in the individual safety protection monitor and radioactive indication for work personnel in the following fields: nuclear power plant, accelerator, iron and steel industry, chemical industry, isotope application, radioactive substance, Cobalt source treatment, lab, etc..    Note: Size and color may be slightly different due to manual measurement and different light conditions. Thanks for understanding.    Specifications:  Color: Black  Material: Plastic  Screen: LCD Digital Display, with Backlight  Ray Detection: X-ray, γ-ray, Hard β-ray  Energy Range: 50keV~1.5MeV≤±30% (as for 137Cs Ⅰ)  Normal Amount: within 0.5μsv/h  Relative Inherent Error: ≤±15% (137CS 1mSv/h)  Detector: Energy Compensation GM Tube (Geiger Counter)  Sensitivity: 80CPM/μSv/h (as for Co-60)  Unit: μSv/h, μGy/h, mR/h  Dose Equivalent Rate (DER) Measuring Range: 0.01~1000μSv/h (Max. 10mSv/h)  Dose Equivalent Rate (DER) Alarm Setting: Select from 0.5, 1.0, 1.5, 2.0, 2.5, 5.0, 10.0, 50.0, 100.0 μSv/h  Operating Environment: -10~45℃, ≤95% RH (45℃)  Built-in Battery: 2 * 3.7V 1200mAh Lithium Battery  Package Size: 13.5 * 7 * 2.5cm / 5.31 * 2.76 * 0.98in  Package Weight: 260g / 9.17oz    Package List:  1 * Digital Radiation Tester