This small realistic looking bar of soap will startle them when they lift it off the soap dish. Just put a harmless cap in the device and then when they lift it up it will make a startling BANG. Great little practical joke for the bathroom, kitchen or any where you place a bar of soap. 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.