The Superior Tool 4500 Drain Key allows you to unlock and install new drains into your bathtub. It has an expanding design that internally grips to the drain in a 360-degree pattern making it easy to unlock your drains and remove them. You can also use a crescent wrench with this Superior Tool drain key so that you can install and unlock various shapes and sizes of drain. This tool expands in the drain using three knurled steel shoes. Turn the drain out with the bathtub drain key using the large nut. Stubborn tub drains are a thing of the past with this extractor tool.