KR002-Gas Detector-Natural Gas-Methane-Propane-CO Alarm Specification Plug-in Carbon Monoxide & Explosive Gas Detector is a smart combustible gas combo detector with sound prompt and 9V battery Backup,continuously dispalys of the gas concentration levels from 100PPM-999PPM(50PPM) and will Voice alarm >85dB when dangerous levels are reached.This detector is a great helper to detect the invisible Gas & CO in the air(such as Natural Gas,Propane,Methane,Liquefied Petroleum Gas,etc)and keep you and your family away from the threat. Feature High Sensitivity Dual Sensor Design Carbon Monoxide fire alarm is a Catalytic Combustion Method Sensor and the Electrochemical Carbon Monoxide Sensor; Protect yourself and your family from two deadly threats. When dangerous concentrations of Carbon Monoxide or Explosive gases are detected, notify you immediately to save your life in the first place. Easy To Use Push/test button - Connect to power 90V-240V or 9V rechargeable battery(not included), The detector will display 3 minutes counting. LCD Digital Display This display clearly shows levels of Gas that the unit has detected and stored-- from 0 to 3000 ppm--and it updates every 9 seconds to indicate any sudden changes. Voice Alarm When the concentration of Carbon Monoxide reaches 100PPM or the concentration of Combustible gas reaches 6%, the LCD screen begins to display the concentration value, and the red LED lights flash and emit a loud voice alarm mode -- 110 decibel alarm. Easy Installation & Quality Easy to mount on any wall or ceiling without an electrician;The detector has been rigorously tested and passed UL2034 safety certification, If you have any questions, Please contact us by E-mail, We will give you a SATISFACTORY SOLUTION. KR001-Gas Detector Specification AV voltage: AV 9V-240V 50-60Hz Battery voltage: 9V rechargeable battery Working temperature: 0-50 C Environment humility: 10%-95% Alarm density: 3000PPM(1500PPM) Alarm time: keep alarming after over 3000PPM Product Size: 112 * 73 * 42mm Features Human voice prompt. High reliable catalytic combustion method. Gas concentration displaying(PPM). Power supply from AC 90V-240V or 9V rechargeable battery (Not included). Intelligent microprocessor control. Auto low battery warning. Alarm memory function. Auto detect sensor failure. Note These two models will not detect the toxic carbon monoxide gas Ordinary detector, no display