EXPIREDAfter testing 12 personal breathalyzers against the alcohol-detecting devices used by law enforcement, it’s clear that the BACtrack S80 is the most accurate and reliable and easiest to use personal breathalyzer that you can buy. When it comes to matching the results measured by police equipment, this device comes closer than anything else we tested. It’s relatively affordable and has everything you need to start testing right away, including replaceable mouthpieces—which are good for accuracy and hygiene, but definitely an ongoing cost to consider. We chose the S80 after testing breathalyzers in several separate drinking sessions last year and this year. In those tests, we cooperated with experienced members of law enforcement in two police departments, and interviewed a research physician who specializes in toxicology.