From their indiegogo page:

ELF emmit: A Wearable for the Optimized Self

ELF emmit improves focus, sleep, stress, & more, combining ancient traditions and modern technology.

ELF emmit uses non-invasive and FDA Approved technology to actively influence positive change in your daily life by emitting pulses at specific frequencies, optimized to attain a desired state of mind, at any given moment.

They claim they can change any one of the 5 brainwave types: gamma, beta, alpha, delta, or theta by emitting “pulses” at certain frequencies.

I have a friend who is a mechanical engineer. He previously worked for companies that manage proton therapy systems. I showed him the indiegogo page and this is what he said:

“Yeah, this is bullshit. In TMS, the instantaneous coil current is actually very high, into the kiloamps. A headphone output will provide maybe 500 mW of power into some fairly high resistance. All they did was put that output through a very small coil. In other words, if this worked, we would be dead if we brought our heads next to a power transformer.”

So yeah. ELF Emmit = Snake Oil. $119 Snake Oil.