This magnetic gun is different from the “snail-oil” magnetic and other devices, which you may have seen on web sites. This device is real and based on sound science. However, it is only practical for a subgroup of migraine sufferers, those who have a clear warning of their migraine (aura) and have a space between that warning and the start of the headache.
We now know that migraine aura is a spreading electrical storm on the surface of the brain. If not stopped, the brain will respond to that storm with a bad headache. Trans-cranial magnetic stimulation stops that storm in its path, thus preventing the migraine headache from occurring. So if you have migraine with aura and have a window of time between the aura and the headache, this might be a significant advancement in your treatment.
The device is not immediately available but will be coming on the market soon. The cost of the device and the insurance coverage will be not be known for a while.