Features： 1、The brake pressure is transmitted by the brake fluid. Once the brake fluid contains too much water, the pressure transmission will fail. At this time you need this brake fluid tester. 2、In order to drive safely, we must regularly test the water ratio of the brake fluid. The brake fluid tester can help us with current maintenance and ensure that we are driving in safe conditions. 3、The brake fluid tester with 30mm gooseneck probe provides sensor flexibility and is more practical and convenient. 4、Hand‑held size, provides one‑handed operation possibility, oil and anti‑oxidation chromium detector. With the dual alarm system with red light and buzzer, the test result is absolutely clear. 5、Processed with high‑quality materials of plastic, wear‑resistant, high‑temperature resistant, and have a long service life. Specification： Item Type: Brake Fluid Tester Material: Plastic How to Use: 1. Install one 9V(6F22) battery at the back of tester. (battery not include) 2. After inserting the battery, press POWER button to turn on the tester, all LEDs lights turn on with buzzer sounding, indicates the product self-test is successful. 3. Press SELECT button, it will locate DOT3 model automatically. 4. Each time you push the SELECT button, it will recycle from DOT3 to DOT4 to DOT5.1 with the indicator LEDs. 5. Immerse the probe into brake fluid, the different colored LED lights mean as below: Green Light: indicates the brake fluid water content is below 1% The First Yellow Light: indicates the brake fluid water content is approximately 1.5% The Second Yellow Light: indicates the brake fluid water content is approximately 2.5% The First Red Light: indicates the brake fluid water content is approximately 3% The Second Red Light: indicates the brake fluid water content is more than 4% 6. Press POWER button to turn off the tester. Package List： 1 x Brake Fluid Tester 1 x Manual