completely legal in most states for anyone over the age of 18 who has never been convicted of a felony. Cost about $350. A single cartridge can shock a victim many times, but to "fire" new probes, a new cartridge is needed (they are replaceable). a background check is required upon purchase. Also, the c2 is available in red, not mentioned in the video.
Carry My C2 everyday. Just the Laser feature is a deterrent. I spoke with an officer today and he is a martial arts instructor and recommends the C2 for his students. He said the Taser is the best tool to come along in the 25 years he has been in Law Enforcement.
Criminal records, drug use, alchohol use, etc. They want to be as sure as possible that you aren't a criminal or a drug addict who's buying a taser for a bank robbery or something.
It doesn't work on the principal of pain. The high voltage electric shocks override the nervous system, causing the muscles to contract involuntarily. Basically, the taser paralyzes you for a brief period of time. Of course, it is painful, but the pain isn't what stops an attacker.