features: Using semiconductor sensors, with high sensitivity, fast response, and simple and convenient use. It will display the final test results in both digital and animated modes, and everyone can self check through this tester. Level 5 result: Very good, normal, not very good, poor, very poor. Digital LCD and cartoon indicators, orange backlight, energy-saving and environmentally friendly, soothing colors, will not harm your eyes. Quick response and recovery, self-examination to display different situations. Portable design, small size, compact structure, easy to carry in a pocket. Non contact design, exhalation distance detector 5-10mm, more hygienic. Power saving design, low battery indicator, 2 AAA batteries can provide long-term use (excluding batteries). Specifications: Sensor type: semiconductor sensor Preheating time: 9s Blowing time: 5 seconds Working environment: Relative humidity: 95% without dew Power supply: 2 * AAA batteries (not included) Product size: 95 * 36 * 18 millimeters/3.74 * 1.42 * 0.71 inches Item weight: 36.6 grams/1.29 ounces Packaging size: 100 * 50 * 30mm/3.94 * 1.97 * 1.18 inches Packaging weight: 45 grams/1.59 ounces Packing list: 1 * Respiratory testing device 1 * Manual