Features:- Two gears can not be used at the same time or it will get burned- Charging: 3 holes are charged separately. Each hole is charged for about 30 minutes one by one. When all three holes are charged, the whole battery is fully charged. When the indicator light of the charger, green light, is off, it means that it is fully charged- Pay attention to the use time: do not use it for more than 10 seconds each time. Use it for 3 times continuously. Take 20-30 seconds to cool down the instrument. Prevent it from burning out due to high temperaturePrinciple:The EMP Generator produces a high-frequency electromagnetic wave field. An energy-saving lamp around the generator induces electromagnetic waves and generates an electric current. When the electric energy is sufficient, the bulb will light up.PS: There is no guarantee that the energy-saving lamp will work. If it is on, it proves that the meter is working.Specification:- Frequency: 150MHZ- Typical applications: Fingerprint lock, slot machines, claw cranes, game machines, etc.- Working voltage: DC 36V- Antenna mode: built-in reinforced antenna + external high-frequency antenna- Power supply voltage: DC 36V- Charging time: 1.5 hours in total- Charger: input110-220 VAC- Built-in rechargeable battery