DescriptionThe brake fluid tester is suitable for determining brake fluid quality.Brake Fluid Tester is according to the variation of electrical conductivity to determine the moisture content of the brake fluid change.It through the light-emitting diodes clearly shows the degree of moisture. High content moisture will reducing the boiling point、 and then affect the braking performance. Red indicates brake fluid need to be replaced immediately、 green indicates brake fluid in good condition、 yellow indicates brake fluid stays good、 but is going to change.Designed without cable connectorFast and convevientPower supply: 1.5V "AAA" x 1 (battery not included)Suitable for DOT3 / DOT4 testingDirections for using:5 LEDs indicating the water % in the brake fluid :0% LED?Battery is OK、and there is on water content in brake fluid1% LED: Water Content、 H2O?1%、 brake fluid is above standard2% LED: Water Content、 H2O?2%、 still can use it3% LED: Water Content Water Content、 H2O?3%、 brake fluid should be changed4% LED: Water Content Water Content、 H2O?4%、 brake fluid must be changed