Check the listing for details. TECHTRONICS | CAJA DE TOQUES-Fully Assembled (280 Volts). Condition: New. Listed at 49.99 USD. TECHTRONICS: CAJA DE TOQUES / Shock Box, Fully Assembled (280 Volts) Party Game Challenge your family and friends if they can resist the fun of different voltage levels 1)Install Battery: Open the bottom cover to install 3 x AA batteries, alkaline batteries are recommended 2) Power On:To switch on the machine ,short press the button 3)Power off: To switch off the machine long press the button 3 seconds untill the led indicator keep lighting (stop blinking) and long beeping, then release the button 4)Game start: Connect the plug of shocking bar to the machine, switch on the machine, led indicator will blink indicate the machine is working 5)hold the electrodes and adjust the knob to get different intensity levels * ‡5% base on battery voltage=4.5V-5V Intensity level | *Voltage(V) | Scale on Knob Level 1 | 85 |1 Level 2 | 100 |2 Level 3 | 130 |3 Level 4 |160 |3.5 Level 5 |170 |4 Level 6 |180 |4.5 Level 7 |200 |5 Level 8 |210 |5.5 Level 9 |220 |6 Level 10|230|6.5 Level 11 |250|7 Level 12|260|7.5 Level 13|270|8 Level 14|275|8.5 Level 15|280|9 Warning: 1) This machine should not be used by individuals with pacemakers, blood pressure problems, or pregnant women, as it may pose a risk to their health. Age 15+ 2) Do not short-circuit two metal shocking bars 3) There is a Micro-usb socket for external 5V power supply however do not use AA battery at the same time usb cable is not included