The bump key is nothing special. You can do the same thing with lock picks and you don't need a special key. It is the same method. On pin tumbler locks you put the "bump key" in and put pressure on the lock by turning the key counter clockwise. Then you use a hammer or some other solid tool and "tap" on the back of the key. What you are doing is moving the pins and if your lucky you will line them up and the lock will turn. With lock picks you use a spring tool to add pressure on the lock by turning it counter clockwise. You then use a "rake" lock picking tool and insert it in the key way and "rake it in and out a few times" and with much less practice the lock will open. Most likely 80% of all buildings and structures have between a "4 pin tumbler lock" and a "6 pin tumbler lock. With a little practice with lock picks you can open most pin tumbler locks in about 2 to 3 minutes.