The BACtrack S80 Pro is a professional breathalyzer that combines advanced features, fuel-cell accuracy and an easy-to-use handheld design. The BACtrack S80 Pro is a professional breathalyzer that quickly estimates blood alcohol content (BAC). The S80 Pro is the perfect choice for law enforcement, hospitals, clinics, businesses, and for personal use anytime fuel cell accuracy is required. The advantages of the S80 Pro's Xtend Fuel Cell Technology are numerous. First, the S80 Pro provides 4 digit test results that can pickup trace amounts of alcohol for example, 0.002 %BAC. This is helpful in zero-tolerance environments where subjects may have had only a small amount of alcohol. Next, the Xtendâ?¢ fuel cell technology extends the range of accuracy all the way from 0.000 - 0.400. Because the S80 Pro shows a linear response to measured alcohol, the S80 Pro will provide more accurate results over the complete range of alcohol concentrations. The benefit of the S80 Pro's Xtend technology also applies to the life of the sensor. The S80 Pro has an extended sensor life as compared to standard semiconductor-based breathalyzers, and will require less frequent service and maintenance. Finally, the Xtend technology also extends the useable battery life up to 1500 tests per set of AA batteries! The S80 Proâ??s Xtend sensor technology is unlike any other available, and is worth the upgrade. Don't purchase a novelty breathalyzer that may not provide trusted results. Go with what the Pros use. The BACtrack S80 has been tested by the DOT/NHTSA and meets their requirements for a breath alcohol screening device. The S80 Pro is also for personal use.