This is a classic practical joke and you can use this to create your own Bang gags It goes off with a loud BANG when the door or seat is open or lifted. Has self stick tape to make it stay in one place. Mainly used on a Toilet lid, but you can use it on cabinets, car doors just about anything that you have to open. How it works is a harmless cap that goes off when it is set off, its just enough to startle and have some fun pranking with this practical joke product. Uses any type of harmless strip caps to get the bang effect, these are not included. Have fun with this classic practical joke to prank your family and friends.