Features: The brake fluid tester pen widely test the percentage of moisture in DOT3 DOT4 DOT5.1 ENV6 ENV4 brake fluid. Easy to use, tap the top to open it, and insert brake fluid tester pen into the water when the green light on, which is simple and fast. The result appears within a few seconds. The five LED lights represent the percentage of water in the brake fluid in green, yellow and red. Developed for professional use in automotive repair shops and in servicing. Small size, easy to carry, requires 1 x AAA/1.5V battery, not included. Specifications: Item: Brake Fluid Tester Pen Material: Nylon Battery: 1* AAA battery(not Included) Size: 15*1.8cm Package Size: 22*7*3cm Package Weight: 52g Note: 1. Due to the different monitor and light effect, the actual color maybe a slight different from the picture color. 2. Please allow 1-3cm differs due to manual measurement. Package List: 1* Brake Fluid Tester Pen