A simple pen tester for something that's so important - your car's brake fluid. Don't take a chance for the sake of carrying out such a simple test.
Detection is based on conductivity to determine the moisture (water) content in brake fluid. High moisture content means a lower boiling point, affecting braking performance. Red indicates the brake fluid needs immediate replacement, green represents a good condition, yellow indicates the state is currently acceptable but will soon need to be replaced.
1, green LED = water content in the brake fluid <1.5%, brake fluid is fine
2, yellow LED lights = brake fluid water content= 1.5% to 3%, can continue to use, test again six months later
3, red LED lights = water content in the brake fluid > 3%, the brake fluid needs to be replaced
Power: one AAA battery (not included)
External Testing Certification: CE