Description: 【Electronic Switch Type Induction Coil】: The electronic switch-type induction coil mainly provides low-power high-voltage power supply for middle school physics and chemical experiments, allowing for continuous adjustment of high-voltage pulse polarity 【Sturdy Construction】: Crafted from quality PP, this instrument ensures durability and longevity, providing a reliable tool for educational purposes 【Wide Application】: It can be used as a high-voltage power supply for low-pressure discharge tubes, cathode ray tubes, Roentgen Ray tubes, and spectral tubes. It can also demonstrate spark discharge in air 【Easy to Use】: Plug the power supply of the instrument into the 220V, 50Hz mains power supply, turn on the power switch, and then adjust the middle knob to generate the required discharge spark 【Simple Adjustment】: To change the direction of the discharge spark, simply turn the reversing switch Specification: Material: PP Input Voltage: 220V, 50Hz Size Chart: L*W*H: 29cmx13.5cmx23cm/11.42inchx5.31inchx9.06inch Package Includes: 1 Electronic Switch Type Induction Coil Note: Please allow slightly errors 1-2cm/0.39-0.79inch differences due to manual measurement.