“So, not a machine gun, then.”
No, the Glock Switch effectively converts a Glock into a machine gun. They are so popular on the street, hardly anyone that can buy or steel a Glock can get one for chump change. Low or high quality made on 3d printers, they are sold on the black market. Probably every bag of fentanyl comes with one like a toy in a cereal box.
They allow you to hold your pistol sideways and empty your magazine in 2 seconds while making your accuracy worse.