7.83Hz Schumann Frequency Generator 0.01Hz-300kHz Adjustable, USB Powered Schumann Generator, Sound Resonator for Research, Testing, Equipment Calibration, and Engineering Applications

Disclaimer: if your evorina registers as another frequency than what's entered, don't fret, that's the machine accounting for inaccuracies, example: 266 shows as 266.24 which makes up for the inaccuracy, 2720 shows as 2727.27 (the 7.27 amounts to the percentage of inaccuracy)

No way to tell if it worked or not. No sound when connected to speakers. No support. I sent it back.

If it had English on it without me having to decipher Chinese to confirm it's actually working I would have kept and spent more time with it.It has an earphone jack and if I had a powered speaker to check frequency output or a way to confirm the standard solfeggio frequencies I would have maybe kept it and made my own box for it.I just use a speaker now at my desk now for just trying to absorb some good energy.

Great little machine- good value for the price and easy to use

Shouldn’t it vibrate or something in some way? I can’t see that it does anything other than light up. And no instructions or anything…Sending it back

I like the idea of the device however it will not go to many of those sounds exactly as you input it. If you input 963 it will generate a sound at 965.25. If you input 9999 it will produce the sound at 1000. If you input 2389 it will Produce the sound for 2396.16.