The BACtrack Select S30 is one of the most portable breathalyzer. Because of its small size which is less than 1" thick and 4" tall, it is perfect for testing anyone, anywhere and easily fits into a purse or pocket for on the go lifestyles. Simply attach a mouthpiece, blow for 5 seconds and an estimate of Blood Alcohol Content (BAC) is displayed in seconds. The S30 uses innovative MicroCheck technology which provides trusted results even with its small size. The sleek black finish makes it attractive to use at any bar, restaurant or anywhere alcohol is consumed. Advanced features include a test counter, low flow error detection and a wide test range from 0.00 to 0.40 %BAC.