1. Model: AHC-4 2. Electrochemistry sensor(Japan) 3. Gas detected: carbon monoxide (The density of gas can be demonstrated.) 4. Size: 163mm*87mm*40mm 5. Working voltage: AC220/AC110, 12VDC-20VDC 6. Back-up battery: 9V alkaline cell 7. Additional function: can work with solenoid valve or manipulator or exhaust fan 8. Networking: wired networking(NO, NC) 9. Patent No.: 200830103202.4 10. Wireless networking mode: 315MHZ/433MHZ (2262 OR 1522