Please be kindly noted，the listed product is produced and distributed abroad and subject to the laws of its country of origin。 Features: Reliable and fast measurement of electric field intensity, magnetic field intensity, radiation power static electricity, etc. If the radiation exceeds the standard, the alarm will sound and the red light will shine. Plastic case + metal electronic core, sturdy and high accuracy. Inductive non-contact test, it has a sensitive response to the radiation generated by household appliances, such as computers, televisions, refrigerators, air conditioners and rice cookers. Suitable for electromagnetic wave radiation pollution test in ordinary household environment, computer room, control room. Specifications: Material: PP Frequency: 50~500Hz Operating Temperature: 32~122℉ (0~50℃) Alarm Mode: Sound and light alarm Power Supply: 2 * 1.5V AAA battery (NOT included) Item Size: 148 * 25 * 20mm / 5.83 * 0.98 * 0.79in Item Weight: 50g / 1.76oz Package Weight: 65g / 2.29oz Package Size: 16 * 3.5 * 3cm / 6.30 * 1.38 * 1.18in Packing List: 1 * Digital Tester