What to know about 'Glock switches,' the devices that make handguns full auto

The ATF and Cincinnati police said Wednesday that they are finding guns illegally modified to make them fully automatic on a weekly basis.

What is a Glock switch?

Also called a "chip" or "auto sear," it's a small device that gets installed on the back of a Glock handgun. Instead of firing one round per trigger pull, the device allows the gun to continue firing at a high rate as long as the trigger is pressed.

Why are they dangerous?

The device demonstrated Wednesday allowed the handgun to empty a 30-round magazine in about two seconds − two to three times faster than pulling the trigger for each round. The ATF explained that using the devices makes shootings more deadly. More bullets can hit the victim, but the weapon is also harder to control so bullets can be sprayed around striking innocent bystanders.

Where do they come from?

Officials said switches are illegally imported from overseas or 3D-printed locally. Because the devices can be made from plastic on a 3D printer, it means the files to make them can easily be shared over the internet.

What is the penalty for possessing one?

U.S. Attorney Kenneth Parker said possessing one of the devices is a federal crime punishable by up to 10 years in prison.

A man was recently sentenced to three years in prison for having one installed on his Glock, which he said he fired in self-defense. Parker said that's no excuse.

This article originally appeared on Cincinnati Enquirer: How does a Glock switch work? 3D-printed device makes gun fully auto