Uses infrared semiconductor sensors, with high precision and stable performance, can accurately detect carbon dioxide value. Adopts air convection design, which can provide more accurate detection results, and the detection range is 400ppm-5000ppm. 4-color circle design, different colors corresponding to different air quality, suitable for office, family and on other occasions. 0-999ppm green color will flash, 1000-1999ppm yellow color will flash, 2000-2999ppm orange color will flash, 3000-3999ppm red color will flash, above 4000ppm 4 colors will flash. Widely applications: agricultural planting, greenhouse vegetables, production warehouse, material processing, home interior, etc. Product size: 11.2*8*3.5cm. Shipping quantity: 1 piece.