2-in-1 Brake Fluid Tire Pressure Tester Pen Accurate Portable Oil Quality Checker with 5 LED Indicator Item Type: Brake Fluid Tire Pressure Tester Material: ABS Enter Tire Pressure Test: 1.Press the Upper button to start testing the tire pressure. The pressure nozzle is pressed against the tire valve,The measurement results appear on the LCD display. 2. Read the tire pressure directly on the display. 3. Press the Upper button continuously to convert the measurement unit. 4. Press and hold the Upper button for 3 seconds to turn off or Press the Down button to close. Enter Brake Fluid Test: 1.Press the Down button to light up the green light and start testing the moisture content of the brake fluid. Open the bottom cover of the product and immerse the metal probe in the brake fluid. Within 1-2 seconds,the test results will be displayed correctly. 2.Automatically shut down after 7 seconds of testing. Indicator Description: 1.Green light: Battery OK, the water content in the brake fluid is 0% 2.Yellow light: The water content in the brake fluid is <2%, which means that the brake fluid can continue to be used for 6 months, and then tested again after 6 months. 3.Red light: The water content in the brake fluid is >3%, indicating that the brake fluid cannot be used any more and needs to be replaced immediately. Attention: 1.When measuring tire pressure, the display shows OL,indicating that the test pressure range is exceeded.Press the nozzle firmly while testing, otherwise it will deflate. 2.Press the Upper button or Down button. The display shows LO,indicating that the battery is low and needs to be replaced. 3.After testing the moisture content of the brake fluid, clean the metal probe with water to prevent corrosion of the brake fluid. 4.Battery: CR1225 or CR1220 (not include)