Originally, the Glock 18 was introduced as a select-fire 9mm for military and police use in 1986, and was originally designed at the request of an Austrian counter-terrorist unit.

The Glock 18 is dimensionally very similar to the Glock 17, with only a handful of differences. One difference is the presence of a turret-shaped selector switch on the right rear side of the slide.

Glock switches are also sometimes referred to as “sear selector switches.” Under federal law, a person can be sentenced to up to 10 years in prison for possessing a gun with a switch ...