Pen tester for measuring the usability of brake fluid in a car

Car brake fluid tester pen. With this tester, you do not need to go to a service station to check whether the brake fluid needs to be replaced or not. Thus, you can save on service station services.   Checking brake fluid is based on measuring the moisture content of the fluid. High moisture content will reduce the boiling point, which affects braking performance. Every motorist should have a brake fluid tester.   Measurement results: 1. The green light comes on: the water content in the brake fluid is minimal, H2O from 0% to 2. Yellow light: H2O water content 3. Red light: water content in brake fluid H2O > 3%, brake fluid needs to be replaced. If two red lights come on, then the fluid is not safe to use and needs to be replaced urgently. 4. The red light is flashing: the battery in the tester needs to be replaced   The TJ tester is powered by an AAA battery (not included)