precision rapid detection: this Professional Alcohol Breath Tester uses an advanced semiconductor alcohol sensor to deliver a measurement range of 0.00019% BAC (0.01.9 g/L) with an accuracy up to ±0.02% BAC at 0.05% BAC. Quick response with results in about 5 seconds helps you quickly understand your alcohol content and drive safely. 12 interchangeable mouthpieces, hygienic and convenient: includes 12 washable and recyclable mouthpieces to accommodate multiple users while maintaining hygiene. Ultracompact and portable for testing anywhere. After drinking, it is recommended to rest for 20 minutes before testing to improve accuracy. Intelligent alarm function, safe driving reminder: when the test result exceeds a preset limit such as 0.05% BAC or 0.50 per mille BAC or 0.25 mg/L or 50 mg/100 mL, the device will beep to remind you to stay safe and not drive. Smart design supports safer driving decisions. LCD display, intuitive and easy to read: the device features an LCD display with clear results at a glance. It supports two units, %BAC and g/L, to meet different preferences. Simple operation: insert 2 AAA batteries (not included) and press the test button to start.