Specification Sensor: 48mm Geiger Counter Measurement range: 0.05usv~50msv Measurement accuracy: -17%~+25% based on 137Cs Working environment: temperature -20~50; humidity <95%RH, no condensation Battery life: 50 hours (continuous measurement of screen sleep) Charging time: 2~3 hours Charging interface: type-C interface (green light is always on when charging, and goes out when fully charged) Size: diameter 15.3mm, length 108mm Weight: 19g Features For people who are not exposed to radiation in their daily work, the normal annual natural radiation is mainly due to hydrogen radiation in the air at 1000-2000 microsieverts. Radiation <100 microsieverts has no effect on the human body. For radiation-related workers, the annual radiation exposure is less than 50,000 microsieverts. A single exposure to 4000 mSv can cause serious damage to human function Product includes 1 x Radiometer