ITEM NAME:2x DC 3.7-7.4V to 400KV High Voltage Generator Boost Inverter Module 67x25mm Description: This high-voltage generator module is based on the principle of Tesla coil. This small high efficiency module can release high-voltage pulse output with simple external circuit power supply. Ideal for students to study electrical experiment, do science experiment, etc. Input: 3.7V - 7.4V / 4A Output Voltage: 400KV/0.5A Specification: Dimension: 67 x 25mm (LxD) Input Voltage: DC 3.7V - 7.4V Input Current: 4A Input Wire Length: 27cm (Red positive Green negative) Output Voltage: 400KV (Please be careful when using) Output Current: 0.5A Output Wire Length: 18cm Discharge Time: 10s Arc distance/High voltage discharge distance range: 2-4cm Power supply: 1x 3.7V Lithium Battery, 2x 3.7V Lithium Batteries in series(such as 18650 Battery), NiCd/NiMH Batteries, 4V/6V Lead-acid Batteries, etc. (6V battery is Recommended for the best effect) Package Includes: 2 Pieces 3.7V to 400KV Step-up Power Module Generator Note: 1. The high-voltage module should not be.2 Pieces 3.7V to 400KV Step-up Power Module Generator. The power of the module is large and the heat dissipation inside is weak. Input Current: 4A. Input: 3.7V - 7.4V / 4A. Input Wire Length: 27cm (Red positive Green negative).