The new multi-use aerator key allows you to remove or install your aerator with ease. Over time, aerators can get clogged with mineral deposits causing erratic or slow water flow, creating a need to clean or install a new aerator. This aerator key has an aerator wrench for internal or external threads, as well as four sizes of keys that fit most faucet brands. While wrenches and other tools can scratch or cause damage to the housing of the faucet, this aerator key was designed specifically for easy, non-abrasive installation and removal of your aerator.