The manual pick gun (or snap gun) was invented by Ely Epstein. It usually has a "trigger" that creates a movement which (like bump keys) transfers sudden energy to the key pins which communicate this to the driver pins causing those pins only to jump, allowing the cylinder to turn freely for a brief moment, until the pin springs return the pins to their locking position. Electric versions are now also common, whereby simply pressing a button the pins are vibrated while the normal torsion wrench is being used.