Specification: Power supply: 3 * 1.5V AA battery Maximum static current: 80uA Maximum alarm current: 30mA Alarm voice: light / sound prompt Sensor: electrochemical carbon monoxide sensor and infrared light bar Temperature: 0 to 50 ° C Relative humidity: 10-95% Carbon monoxide sensor detects concentration: 000-999 PPM Sensitive smoke detector: 0.1% db / m - 9.9% db / m Alarm display: LCD display, light / sound announcement Capacity Battery: Low battery alarm Dimensions: 104 * 39 mm Package list: 2 * Combination smoke and carbon monoxide alarm 2 * Set of mounting screws 2 * User manual Function: 1. Combination smoke detector and carbon monoxide detector 2. LCD display PPM concentration 3. High-precision electrochemical sensor and infrared light barrier 4. Easy installation, no need to debug