Fangrui Product Details 1. Utilizing Tesla Coil Principles, This High-voltage Module Outputs A Fierce Discharge With High Efficiency And Compact Size. Simple To Integrate, It Requires Only A Switch And A Battery Connection. Ideal For Applications Needing A Robust High-voltage Pulse. 2. Flexible Power Options Include A Single 3.7v Lithium Battery Or Two 18650 Batteries In Series. For Optimal Performance, Use Batteries With A Capacity Over 2000mah, Removing Any Existing Protection Board From Idle Mobile Phone Batteries. 3. The Module Accepts An Input Voltage Of Dc 3.6-6v And Boosts It To A High-voltage Output Of Dc 20000v. Connections Are Straightforward: Red For Positive And Green For Negative Input; Output Cables Maintain The Same Color Coordination. 4. For Educational Purposes In High Schools Or For Diy Electronic Projects. This 20kv Boost Step-up Module Can Also Serve As A Negative-ion Generator Or A High-voltage Source For Various Scientific And Experimental Applications. 5. To Ensure Safety And Equipment Longevity,