You are getting a bandana with Mental Wave. You can use it in several ways with the device. We are sharing two ideas to work with the bandana. If it is you who receive the information, then you can also choose between the two methods. Always ensure the bandana is tight so that the contact against the head is adequate.
Here's a simple trick using a regular bandana. Ask someone to place the bandana on their head. While they do that, secretly palm the device in your hand. Go to the spectator, gently place the device under the bandana while you move the back to their nape (back of their neck) while pretending to adjust it on their head. It will look like the bandana is still on their head, but it's now also covering their nape with the hidden gimmick.
To finish the trick, smoothly remove the bandana from their head, making sure to hide the gimmick at the same time. The great thing about this setup is that the bandana can be thoroughly examined at the beginning and end of the performance. It can even be given to the audience for inspection.
Another solution is hiding Mental Wave inside the bandana and conveniently putting it on the spectator's or your own head. For this, make a small hole to form a small pocket to insert the gimmick.
This way the bandana is not examinable, however, it is easier to set it up.
After Mental Wave is installed on the spectator's head here's a basic way to test that everything is working properly: