I'm sure there is something out there that could work for magic, but there isn't a product currently on the market that is made specifically for magician's use. None that I know of at any rate. However anything that you would want to use that would be truly deceptive, or invisible, operating on a private frequency that won't interfere with other radio signals, and be approved by the FCC without the need for a private operators license (which can be costly) is going to be expensive. I'm talking several hundred to a few thousand dollars for the ear piece, transmitter, and battery pack. Honestly, your much better off getting 13 steps to mentalism and learning how to do a billet switch, maybe pay $60 bucks for a nice billet knife or something.