Features: Only takes seconds to know the results,very easy to use. Quickly to check whether it qualified, which can remind you to change the brake fluid when necessary to avoid traffic accident. The LED indicators will show percentage of water in the brake fluid with 3 colors green, yellow and red. Calibrated for car using DOT4 and DOT3 brake fluids (But DOT3 almost replaced by DOT4 because DOT4 has better performance). Small size ,you can take it in pocket , take 1xAAA 1.5V battery(Not included). Specifications: Material: ABS+Stainless Steel Power supply: 1xAAA battery(Not included) Note: Please allow 1-3cm error due to manual measurement. please make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Package includes: 1x Brake Fluid Liquid Tester