FEATURES: PORTABLE: Designed using an ultra-sensitive semiconductor sensor system our portable breathalyzer accurately displays blood alcohol level in seconds.EASY TO READ: The Alcohol Tester provides you with highly accurate test results that reliably withstand high values. The red background light makes it easy to read even at night.ALARM FUNCTION: The breathalyzer warns you with an audible alarm if the measurement exceeds 0.5 BAC.In order to save power, the breathalyzer switches off automatically 5 seconds after the test is completed.In addition, it has a battery level indicator.One-Touch Operation: The Breathalyzer is very easy to use.Simply insert two 1.5V AA batteries (batteries not included), turn on your breathalyzer and start testing.You can easily change the unit of measurement and set custom BAC thresholds for testing.