Specification: Item Type: Brake Liquid Tester Pen Material: ABS+Aluminium Alloy Color: BlackLength: Approx. 145mm/5.7inBattery Type: AAA alkaline battery (NOT Included)Fitment: Universal Instructions for Indicators:1. Green The battery is OK, there is no water in the brake fluid 2. Green / Yellow The water content of the brake fluid is less than 1%, and the brake fluid has good performance and can be used with confidence.3. Green / Yellow / YellowThe water content of the brake fluid is about 2%, and the brake fluid can be used continuously. 4. Green / Yellow, Yellow / Red The water content of the brake fluid is about 3%. It is recommended to replace the brake fluid. 5. Green / Yellow / Yellow / Red / Red The water content of the brake fluid is at least 4%, the brake fluid needs to be replaced immediately Test Steps: 1. Please change the battery when the red LED flashes 2. Turn on the switch when all the lights are on, please remove the battery to restart 3. After the switch is turned on, please release the button to measure. Package List:1 x Brake Liquid Tester Pen