The BACtrack S35 Breathalyzer is one of the smallest, sleekest units on the market. Designed in California with ease of use and style in mind, the S35 harnesses a powerful proprietary sensing technology and a specially tuned algorithm, delivering results with unheard of accuracy at this price point. You won’t believe the comfort and security you feel with this tiny unit in your pocket. Just pull it out, turn it on, and blow into it for five seconds. Your estimated BAC will display on the cool, Caribbean blue LCD screen.