The brake fluid test pen is used to test the quality of the brake fluid. The test result of the percentage of water content of the brake fluid is displayed by the number of 5 LED lights on the test pen. The FT123 brake fluid detection pen measures themoisture change of the brake fluid according to the change of electrical conductivity. The light emitting diode clearly displays the degree of moisture content. High moisture content will reduce the boiling point and affect the braking performance.The red light indicates that the brake fluid needs to be replaced, the green light indicates that the condition is good, and the yellow light indicates that the condition is acceptable. Performance characteristics Powerful function, simple operation; accurate measurement, safe to use; Detect all brake fluids; with automatic shutdown function; Can test DOT3/4/5 brake fluid. Product Instructions Green: the battery is OK / no water; Green/Yellow: Moisture content less than 1%; Green/yellow/yellow: the water content is close to 2%; Green/yellow/yellow/red: the water content is close to 3%, it is recommended to replace the brake fluid; Green/Yellow/Yellow/Red/Red: The water content is higher than 4%, dangerous, the brake fluid must be replaced immediately. Note: The above data is for reference only; Battery: 1 No. 7 AAA battery, open the battery cover in the direction indicated by the arrow on the test pen. (battery not included) Notice 1. If you press the power button for a long time and the green LED light still does not light up, you need to replace the battery; 2. After each use of the test pen, please wash the test probe with clean water; 3. Please do not expose the brake fluid to the air for a long time, because the brake fluid has strong water absorption. Preparing for the test Unscrew the cap of the brake fluid reservoir and remove the cap of the test pen. Immerse the test probe in the brake fluid in the reservoir. water content test Press the power button and the green LED will light up. Hold for 1 second, the test result will be displayed by the lighting of the LED light, after the test is completed, the test pen will automatically turn off after 12 seconds. Shipment Quantity: 1 Piece Package Contents: Only the above package contents, excluding other products. Size: 15.5*1.8cm (Reminder: The size is measured by hand, please allow 1-2 cm measurement error) Colour: Black (Due to different monitors and lighting effects, the actual color of the product may be slightly different from the picture color.) WUZHOU