9/16 inch Wrench is for brake service and slack adjuster installation on heavy-duty trucks equipped with slack adjusters. 7/16 inch Wrench is for brake adjustment on heavy-duty trucks equipped with slack adjusters The 5/16 inch double square ratcheting wrench provides reversible ratcheting action with an angled head for easier operation Automatic Slack Adjuster Release Tool for air systems on heavy-duty trucks, long-haul trucks, and trailers; Brake adjustment tool improves brake service Fork-end designed tool to fit securely under the pull pawl, allowing hands-free operation, Manufacturer: Akfldms