Features: 100% brand new and high quality! Developed for professional use in astomotive repair shops and in servicing. Quality is tested and included on five LEDs in terms of "per cent of water in the brake fluid". Ready for Brake Fluid Test. Unscrew the brake fluid reservoir,and pull off the cap of the Brake fluid tester. Dip the test probes into the brake fluid up to the plastic rim of the device, to check Fluid Quality. Press the button for power on,green LED will light up.Insert the tester into reservoir for one second then the tester result will be correctly indicated by LEDs. Repress the button for power off. The tester will automatically power off after about 15 seconds of inactivity. The tester can be used as a digital brake fluid tester suitable for determining brake fluid quality. Specification: 1. To check the quality of brake fluid quality 2. 5 LEDs to indicate percentage of water in the brake fluid 3. Automatically power off 4. Operated by a LR03 AAA 1.5V battery (Not included) Tester Instructions: Brake fluid detection pen is based on the change in conductivity to determine the moisture change brake fluid. It shows clearly the extent of moisture contained by the light-emitting diode, high moisture content will lead to lower boiling point, affect braking performance. Red indicates the brake fluid needs immediate replacement, green represents good condition, yellow indicates the state is acceptable but soon replaced. 1. the green LED lights = water content in the brake fluid H2O less than 1.5%, brake fluid qualified 2. the yellow LED lights = brake fluid water content H2O equal 1.5% to 3%, can continue to use, test again six months later 3. the red LED lights = water content in the brake fluid Hydrogen molecule2 Oxygen molecule greater than 3%, can not continue to use the brake fluid needs to be replaced Red LED: change brake fluid 4.LED red flashing: battery replacement 5.LED yellow: low moisture content, check again in six months 6.LED green: brake fluid lines / cell row Tester Features: Five LED indicators show the test results more accurate. Testing DOT 3, DOT4, DOT5 brake fluid Press the switch to turn on the power, the green LED light that represents the battery properly, the green light does not shine on behalf To replace the battery Automatic shutdown Technical parameters: Green: Battery OK, that is, brake fluid does not contain water Green / yellow: brake oil in water content of less than 1%, better brake fluid performance, ease of use. Green / yellow / yellow: brake oil in water content of about 2%, brake fluid can continue to use. Green / yellow / yellow / red: brake oil in water content of about 3%, the proposed replacement of brake fluid. Green / yellow / yellow / red / red: brake oil in water content of at least 4%, the brake fluid must be replaced immediately responsible for very dangerous. Color: black Weight: 27g Dimension: 15.5*2*2cm Packaging Included: 1 * brake fluid tester