Features: Wall-mounted 4-in-1 multifunctional carbon dioxide detector, CO2, tempreture, humidity, CO2 alarm function. When the CO2 concentration up to 1000ppm, the alarm will be louding, can be turned on and off, manual operation. Infrared sensor real-time monitoring carbon dioxide concentration, temperature and humidity. With clock and record function, improve daily life practical. High definition digital display large screen, real time monitoring digital change. Built-in fan to draw in ambient air for more accurate real-time results. Rechargeable large capacity cell, USB cable, lengthen service time.