The TEC 9 is a cheap, open-bolt handgun manufactured in the United States between 1980 to 1994 by Intratec. It is based on the Carl-Gustav M/45 submachine gun, more commonly known as the "Swedish K". Originally it was designed as a low-cost alternative to the M/45, but never found a military market. Not wanting to abandon the idea, Intratec put semi-automatic versions onto the civilian market. It gained infamy after criminals found the open-bolt design to be easily convertible to be fully automatic.