2 IN 1 Brake Fluid and Tire Preure Tester Description:1.The tester can check the car brake oil quality and tire preure test, high precise and portable 2 IN 1 tester.2.3 LED lights display the percentage of moisture content in the brake fluid,Testing DOT 3, DOT4, DOT5 brake fluid.3.It is with Digial LCD Detction Display screen.4.Tire preure protection, Kpa / Psi / Bar preure units can be selected by switch button.5.Heavy preure is preure measurement, light preure is deflation.6.Battery:1 pcs CR1220 button battery (not included).Instructions:Brake fluid detection pen is based on the change in conductivity to determine the moisture change brake fluid. It shows clearly the extent of moisture contained by the light-emitting diode, high moisture content will lead to lower boiling point, affect braking performance. Red indicates the brake fluid need to immediate replacement, green represents good condition, yellow indicates the status is acceptable but soon need to replace.1.Green LED light:Water content 0%,the tester start normally/The brake fluid performance is good,there is no water in brake fluid.2.Yellow LED light:Water content 3%,the brake fluid need to be replace immediately. Notice: 1.When measuring tire preure, the display shows OL indicating that the test preure range is exceeded. Pre the valve at the time of inspection, otherwise it will deflate. 2. Pre the key or the key. The display shows LO, indicating that the battery is low and needs to be replaced. 3. After testing the moisture content of the brake fluid, please clean the metal probe with water to prevent corrosion of the brake fluid.