Devon and Cornwall police have unveiled the latest weapon to be used in their battle against violent criminals.
Police officers welcome the introduction of tasers.
The taser stuns offenders with an electric shock but is not designed to kill them.
The taser has been on trial with five police forces in Britain following use in the United States.
Amnesty International claims at least a hundred people have died in America after being hit by its electric shocks from the guns.
Steve Ballinger, from Amnesty, says it's too early to introduce it: "We don't want to see wide deployment of a device which inflicts intolerable pain at the touch of a button and has actually been cited in the United States as a cause of death, without there being very stringent test.
Northamptonshire police was one of the forces to have trialled the weapon.
Sgt Simon Williams said: Extensive testing was done by the Police Scientific and Development Branch. These tests showed the risk of significant injury were extremely low.
"I think the other factor you have to bear in mind is the incidents in which tasers are going to be used.
"That is by its very nature incidents which are extremely dangerous to either police officers or members of the public so the alternative is to use a greater use of force which we wouldn't want to use.
"Police officers don't want to use any more force than is necessary and tasers fill the gap."
In two years Northamptonshire police say they have only used the taser on three occasions.
The guns will be used only by trained firearms officers in the Devon and Cornwall force.