Brake Fluid Tester
This brake fluid tester uses technology via the integrated circuitry to check for the moisture content within the brake fluid by measuring the electrical resistance. The 3 LED lights are used to show if the moisture content is low enough for the acceptable limits.
The item uses a AAA 1.5Volt battery which is included.

Green LED = Brake Fluid H2O < 1.5%
Brake Fluid OK / (Also = Battery OK)

Yellow LED = Brake Fluid H2O < 1.5%~3.0%
Low Percentage of Water
Advisory to Change Fluid within 6 months

Red LED = Brake Fluid H2O > 3.0%
Brake Fluid Change Required