High-concerned chemical: None : Recommend Age: 14+y Electromagnetic Experiment with Space Separation and Electricity Extraction DIY Technology Elementary School Electrical Science working principle can be effectively transmitted between two objects with the same resonance frequency, while the interaction between objects with different frequencies is weak Schematic diagram of wireless charger By coupling through two inductive coils, the current output by the secondary coil is converted into direct current through the receiving and converting circuit to supply power to the LED lamp Wireless charging technology utilizes magnetic resonance to transmit electrical in the electric and magnetic fields between the charger and the device, while coils and capacitors form resonance between the charger and the device. Notes: Please allow 1-2cm error due to manual measurement. Due to the difference between different monitors, the picture may not reflect the actual color of the item, hope you can understand. Color: As Shown Material: plastic Package Contents: 1*Electromagnetic Experiment kit Only the above package content, other products are not included. Note: Light reflection 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.