1, With CE&EN50291&RoHS Approval 2, Electrochemistry Co Sensor 3, Visual and audible alarm function 4, Alarm Current: 20mA ... ~40 minutes 300ppm, Alarms Within 3 minutes4.Alarm Current: ≤20mA5.Sensor: Electrochemistry Carbon Monoxide Sensor6.Superbright LED Display7.Alarm Sound:≥85dB ...