home security system with CO2 sensor direct from Wanlin Fire Protection — 12-year factory experience, WL-HS107 certified CE/FCC/RoHS/REACH/ISO9001/NFPA 72. Key specs: 4G LTE + WiFi + Solar Option + Remote Management, 4G LTE Primary + WiFi Backup + SMS + Push + Phone Call + Email. No monthly fees, 4G cellular backup, DIY installation, expandable to 50-100+ s···