1. Integrated power switch, making it easier to turn on and off the power, eliminating the need to plug and unplug the charging port every time you use it 2. Dual power port design, no longer worrying about incorrect data cable interfaces 3. Unique addition of static protection and short circuit protection on the board, safe and reliable 4. chips are used for more stable frequency and pulse width 5. Added a power switch, turning it to the ON position to turn on the power and the OFF position to turn off the power Schumann wave generator Power supply voltage: 5V 1. chips are used for more stable frequency and pulse width 2. Double layer FR-4 1.2T-PCB board, with stable and more reliable PCB quality 3. Increase the emission coil, enhanced 28 coil emission coil, and increase the emission range 4. The board supports two power interfaces: TYPE C (supports forward and reverse insertion) and USB Micro, so you no longer need to worry about finding different charging cables 5. protection circuit, adding high-power electrostatic protection tube to prevent hand and air static electricity from damaging the chip. 6. Add a PPTC self recovery fuse to prevent the power supply of the board from being completely cut off after a short circuit occurs. When the short circuit is resolved, the fuse automatically returns to normal, making use and more reassuring. 7. Added a power switch, turning it to the ON position to turn on the power and the OFF position to turn off the power. Note: It does not come with a USB power cord. You can use a Type-C universal mobile phone power cord to plug into the interface to power on. It can be used when the indicator light is on. No adjustment is required. Colour:black+silver Material:PCB+Metal Package Contents: 1 x SchumannWave Generator 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.