A level is a valuable tool for all sorts of projects around the home. Whether you're doing something relatively simple such as hanging a mirror on the wall or you're installing a wall-mounted cabinet, you want it to be straight. Having a level helps to take the guesswork out of these jobs. With this tool in your hand, you'll know for certain if what you're hanging is level or not. You can find a wide range of levels for sale at any hardware store.