Brake Fluid Tester Pen 5 LED Indicator Display for DOT3/DOT4 eElectronic Pen Brake Fluid Oil Tester Digital Auto Testing Tool Description: Test the car brake fluid quality quickly to check whether it's qualified, which can remind you to change the brake fluid when necessary to avoid traffic accident The LED indicators will show percentage of water in the brake fluid with 3 colors green yellow and red Calibrated for cars using DOT4 and DOT3 brake fluids (But DOT3 is almost replaced by DOT4 because DOT4 has better performance) Only takes seconds to know the results,very easy to use CE and RoHS approved. Protective cap included.Takes 1 x AAA/1.5V battery (not included) The tester can be used as a digital brake fluid tester suitable for determining brake fluid 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. Tester 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 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.