The high-voltage module is made by using the coil principle, and outputs high-voltage pulse high-voltage current, small volume, high efficiency, simple peripheral circuit (just need to connect the switch, the battery can be) the discharge intensity is fierce. About 20kv boost step up power module the power supply: you can use a single 3.7V lithium battery or two series, such as 18650 battery, idle mobile phone battery (to remove the protection board, recommended capacity above 2000mAh). The input voltage of the arc generator is dc 3.6-6V and output dc 20000v high voltage, input wiring: red - positive; green - negative; output wiring: the other side same color cable. 20kv boost step up module can be used as high-school scientific experiments, electronic devices, negative-ion generator, high-voltage source, to use when small science. The high-voltage module should avoid the use of high-voltage current without a load. Power must be set to a suitable distance to the high voltage output line, the battery capacity is proportional to the distance and the use of the high pressure arc (not a voltage as high as possible, must provide sufficient current). Colour:black Material:Metal Package Contents: 3 x high voltage transformer Only the above package content, other products are not included. Note: Light 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.