This breath alcohol tester is used to measure concentration of the alcohol in human body. With sensitive semi-conductor sensor, this portable breathalyzer can quickly give a result to judge whether you can drive or not. Powered by 2 x AAA batteries( not included, but commonly available), this breathalyzer will automatically shut off to save power after finishing the test for 5 seconds. Each time you install batteries, you can test more than 200 times. This alcohol breathalyzer is space-saving, lightweight. It is easy to hold and carry. Pocket-size allows you take it anywhere and anytime, ensures your safe driving after drinking.