Working Temperature:10-50 Power Supply:Built-in Rechargeable Lithium Battery Specifications:DM1209B-CO Celsius, DM1209B-CO Fahrenheit Screen Display:LED Range:0-500ug/m Product Name:Carbon Monoxide Quality Detector Type:Respiratory Dust Sampler Continuous Working Time:480 Minutes The Impact of Different Carbon Monoxide Concentrations on Individuals 50ppm: The highest allowed concentration for adults. 200ppm: Mild headache, dizziness, nausea within (2-3) hours 400ppm: Forehead pain within 2 hours, life-threatening after 3 hours. 800ppm: Headache and nausea within 45 minutes, death within (2-3) hours 1600ppm: Headache and nausea within 20 minutes, death within 1 hour. Colour:A:Black Material:Plastic Package Contents: 1 * Carbon Monoxide Detector Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.