Features: 1.The brake oil detection pen measures the change in moisture of the brake oil based on the change in conductivity. 2.It clearly shows the degree of moisture content through the LED. High water content will cause the boiling point to decrease, affecting the braking performance, and corrosion of the brake master cylinder and the sub-pump, causing rust and seizure. 3.Red light indicates that the brake oil needs to be replaced immediately, green light indicates good condition, and yellow light indicates that the condition is acceptable, but it is about to be replaced. 4.This product can be used by car 4S shop and owner, the product operation is simple, accurate and fast! 5.Suitable for a variety of models, easy to use. Specification: Features:_x000D_ _x000D_ The brake oil detection pen measures the change in moisture of the brake oil based on the change in conductivity. _x000D_ It clearly shows the degree of moisture content through the LED. High water content will cause the boiling point to decrease, affecting the braking performance, and corrosion of the brake master cylinder and the sub-pump, causing rust and seizure. _x000D_ Red light indicates that the brake oil needs to be replaced immediately, green light indicates good condition, and yellow light indicates that the condition is acceptable, but it is about to be replaced. _x000D_ This product can be used by car 4S shop and owner, the product operation is simple, accurate and fast! _x000D_ Suitable for a variety of models, easy to use. _x000D_ _x000D_ Detailed Description of the Indicators:_x000D_ Green: The battery is OK, that is, the brake oil does not contain water._x000D_ Green/yellow: The water content in the brake oil is less than 1%, the brake oil performance is good, and you can use it with confidence._x000D_ Green/yellow/yellow: The brake fluid has a water content of about 2% and the brake fluid can continue to be used._x000D_ Green/yellow/yellow/red: The moisture content in the brake fluid is about 3%. It is recommended to replace the brake fluid._x000D_ Green/Yellow/Yellow/Red/Red: The brake fluid contains at least 4% water, and the brake fluid needs to be replaced immediately._x000D_ Tips: After each test, wipe the liquid part of the test point with a dry cloth or paper._x000D_ _x000D_ Specifications:_x000D_ Condition: Brand New_x000D_ Material: Plastic_x000D_ Color: Shown as picture_x000D_ Battery: 1 * AAA Batterynot included_x000D_ Weight: Approx.38g/1.3oz_x000D_ _x000D_ Package List:_x000D_ 1* Detection Pen (Battery is not included) PackageList: