Two gears can not be used at the same time or it get burned Charging: 3 holes are separately. Each hole is for about 30 minutes one by one. When all three holes are , the whole battery is fully . When the indicator light of the charger, green light, is off, it means that it is fully 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- to cool down the instrument. Prevent it from burning out due to high temperature Frequency: 150MHZ Typical applications: Fingerprint lock, slot machines, claw , 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 Plug Type:US Plug,it applies to Canada, India,Mexico, Thailand, the , the Philippines,Taiwan and so on. Material: plastic colour: black Voltage: AC100-240V Package Contents: 1 x EMP Generator kit 1 Adapter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.