Product details: Name: Portable Breath-type Alcohol Tester for Cars In-car Breath-type Alcohol Tester for Cars Portable Alcohol Tester Digital Alcohol Tester Material: ABS Color: Black Note: This product does not contain batteries, applicable: No. 7 batteries Measurement object: Alcohol concentration in breath Detection method: Semiconductor gas sensor Using temperature range: -5℃45℃ Storage temperature range: -20℃50℃ Features: Automatic shutdown, fast response. The alcohol tester has a keychain for easy carrying Adopting advanced semiconductor alcohol sensing technology, it quickly collects breath samples and provides blood alcohol content (BAC) estimation The LCD display will show your degree of drunkenness, whether it is dangerous (more than 0.05% bac), unsafe (approximately 0.02% bac) or safe (below 0.02% bac). When the result is between 0.02% - 0.05%, it will display "Warning" and when the result is equal to or higher than 0.05%, it will display "Danger". Battery: 2 'AAA' alkaline batteries (batteries not included) Accuracy: 0.01% BAC (0.1 g/l) Use: 1. Start the test 20 minutes after drinking. Use the alcohol tester and press the on/off key for 1 second. After a "beep" sound, the LCD screen of the tester will be activated. 2. Enter the preheating mode, the display shows Warmup, and in the preheating mode, it will enter the countdown from 10 to 00! 3. After the Warm up mode is over, the display shows the Blow sign, and the countdown from 10 to 00 starts in this mode. During this period, hold the mouthpiece and blow with medium force for 3-5 seconds! 4. If the alcohol concentration range is 0.02%BAC (0.2g/l)-0.05%BAC (0.5g/l), the warning "Caution" sign will appear; if the alcohol concentration range is ≥0.05%BAC (0.5g/l), the warning "Danger" sign will appear, and there will be a prompt sound! 5. The blood alcohol concentration will automatically shut down after 10 seconds. In order to achieve more accurate test results, it is recommended that users repeat the test 2 to 3 times. Note: When the tester is taken out of the package for the first time or has not been used for a long time, the sensor forsurface will be oxidized. The user needs to preheat the product several times before performing the alcohol test! Product includes: 1* Portable car breath alcohol tester Note: Please allow slight size errors (12 cm/0.390.78 inches) due to manual measurement, which shall prevail in actual receipt; please allow slight color errors under different monitors.