Both ends of the tool can be used. Simply select the end which fits best in the drain. Superior Tools Tub Drain Wrench is the only tool of its kind that can be turned from either end with a 3/8 inch or 1/2 inch ratchet wrench and extension, adjustable wrench, or heavy-duty screwdriver. Additionally, this tool installs or removes 1/2 inch square plastic toilet seat nuts. Kohler and American Standard are intellectual property of those respective companies.