ITEM NAME:Brake Fluid Tester Electronic Pen For Multibrand Car For Dot3/4/5 Car Diagn B7C3 Brake Fluid Tester Electronic Pen For Multibrand Car For Dot3/4/5 Car Diagn B7C3 Brake fluid detection pen is based on a change in conductivity to determine the humidity change the brake fluid. This clearly shows the degree of moisture contained in the LED, a high moisture content will lead to a lower boiling point, affect the braking efficiency. Red indicates the brake fluid needs urgent replacement, green color symbolizes good
