There was a post here saying that the Viber 125Hz* that I bought didn't work, or at least I had no idea if it worked or not. This was based on a misunderstanding. I thought the vibrations would be unnoticeable and since there isn't a light indicating if it's on or not, would not know if it were on/charged/in working condition or not.

This is based on a misunderstanding. You do feel the vibrations, but you need to do this to get it on:
-Charge long enough.

-Detach from the charging cable.

-Press the on/off button two times.

I feel the need to set this straight and also to bring attention to this (probably) great and really cheap device. If anyone wants to buy one: I got two for some reason, so I am selling one (without the jelly mouthgard).

*If I'm correct it's a dupe of the Vpro, the Acceledent alternative that you only need to use for 5-10 minutes. The Viber 125Hz switches off after 10 minutes. You can use it alongside braces or to maximize Mewing potential.

The benefits of the Vpro: