The Powerbuilt Brake Fluid Tester is the perfect addition to your garage. This handy, compact diagnostic tool makes it quick and easy to check the moisture content in brake fluid. The built-in LED lights indicate whether fluid is good, okay, or bad. It works on all vehicles using DOT4 brake fluid. Any automotive specialty tool makes an automotive repair or maintenance task easier, but Powerbuilt takes the concept of ‘help’ a big step further. Every package comes with professionally written usage instructions and photos that take you step by step through proper tool usage.