Features: brand new and high quality 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. PS: There is no ensure that the energy-saving lamp will work. If it is on, it proves that the meter is working. Pay attention to the use time: do not use it for more than 10 seconds each for time. Use it for 3 times continuously. Take 20-30 seconds to cool down the instrument. Prevent it from burning out due to high temperature. Principle: 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. Two gears can not be used at the same for time or it will get burned. Specifications: Frequency: 150MHZ Color: black ,white (optional) Typical applications: Fingerprint lock, slot machines, claw cranes, game machines, etc. Working voltage: for DC 36V Antenna mode: built-in reinforced antenna + external high-frequency antenna Power supply voltage: for DC 36V Charging time: 1.5 hours in total Charger: input110-220 VAC Built-in rechargeable battery Size: approx. 85x40x23mm/3.35x1.57x0.91in Package Includes: 1 Set x EMP Generator note: Intermittent work (one click). Cannot work continuously. There are not many machines that can be scored. Try more machine location. Test Before Use: The EMP generator can light up an efficient bulb without power on. When the instrument is close to the luminous tube part of the lamp, and the lamp will light up, indicating that the quality of the instrument is good. It can be used for related tests. Do not for touch the transmitter power coil of the instrument, otherwise the power will be reduced and affect the use of the instrument.