Brake fluid tester pen type

To check concentration of water in the brake fluid
It is necessary to push the TEST button continually during the examination
First, the red LED light will run one and half time from red to green
After it comes back to green LED light, you can start to test the brake fluid
Immerse probe of the tester into brake fluid(probe tip must be at least 10mm above bottom of fluid reservoir)
3 LEDs to indicate percentage of water in the brake fluid (> 3%, 1.5-3%, <1.5%)
Automatic shut - off function (~16 s)
Integrated work LED
Operated by battery 1.5V AAA (not included)
To save the power, taking out the battery while not using for a long period
While pushing the TEST Button and the red LED light is flashing, please change the battery