This version of Shumanbo is equipped with a power switch. No need to plug and unplug the power supply back and forth. by hand Power can be supplied through the Type-C interface of the charger or power bank Additionally, the circuit board has an egg yellow color (light yellow is warm light and helps with sleep) The sleeping light bulb flashes at a frequency of 7.83 times per second. The speed is relatively fast. Hign-concerned Chemical:NONE Model Number:7.83Hz Schumann Resonances Generato DIY Supplies:ELECTRICAL Type:7.83Hz Schumann Resonances Generator Key Word:Resonances Generator (The product appearance and printed words may vary depending on the batch, but this does not affect use) Color: As Shown Material: plastic Package Contents: 1 * Audio Resonator 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.