Detecting range: 0-999ppm Alarming range: 0-50ppm Resolution: 1ppm Sensor: Electrochemical sensor Power Supply: one 1.5V No.5 battery Dimension: 86X58X19mm Weight: 98g Case: Shock-resistant composite material Working conditions: Temperature: -20 to 50 centigrade Humidity: 15 to 95%RH