Feature: 1. It can be used for family, laboratory, offices, hotels, schools, factories, conference rooms, airports, hospitals, restaurants, and many other public places. 2. Large LCD screen, digital display, more intuitive, convenient. 3. High precision, more accurate detection, can detect the environment at anytime and anywhere, to ensure timely detection of air quality problem. 4. Hook hole is set on the back of the instrument, which is easy to install, also can put on the table. 5. With 3.5mm plug hole that can be used to connect external speaker(not included), more convenient to use. 6. Real-time refresh less than 3s, fast measurement can obtain more stable measurement value. 7. The dual-channel receiving window enhances the reference signal compared with the single-channel sensor, make the measurement more accurate. Specification: Condition: 100% Brand New Item Type: Carbon Dioxide Detector Material: Plastic + Electron Color: As shown in the picture Size: Approx.20.9x13x2.8cm / 8.2x5.1x1.1in Weight: Approx.572g/20.2oz Effective Range: 0~3000ppm Maximum Range: 0~5000ppm Resolution: 1ppm Accuracy: ± (50ppm + 5% x display value) Single Response Time: <3s Comprehensive Time: ≤25s Sensor: For Plantower DS-CO2-20 Power Supply Mode: DC5V 1A MICRO USB interface Operating Temperature Range: -10~+60°C Operating Humidity Range: 10%~80% RH StorageTemperature Range: -20~+60°C Mean Time Between Failures: ≥ 3 years Alarm Output: √ Alarm Prompt: Sound + display alarm Package List: 1 x Carbon Dioxide Detector1 x Data Cable1 x Instruction Manual Note: 1. Please allow 1-2cm error due to manual measurement. Thanks for your understanding.2. Monitors are not calibrated same, item color displayed in photos may be showing slightly different from the real object. Please take the real one as standard.