What is cooler than using a spring loaded nail set or hinge remover, rather than smashing your fingers trying to do the same job with a hammer and screwdriver? NOTHING. In addition to resulting in less finger smashing, these tools are also tiny, (they fit in your pocket,) and don’t slip and gouge expensive woodwork and hinges. While I am not a physicist, they seem to work on the principle of concentrating a large amount of energy from their spring, behind a small surface area. While they may not work on a rusted hinge, they create plenty of force for all but the worst situations. I looked at these items on the shelf for over a year before buying one, because I simply couldn’t believe they would actually work as advertised. Be assured that the DO work, and add them to your kit as soon as possible!