X-Sense Wireless Interconnected Combination Smoke and Carbon Monoxide Detector with LCD Display 10-Year Battery, Over 820 ft Transmission Range, 6-Pack Please Note: SC07-W supports wireless interconnection but does not have Wi-Fi. Hear an Alarm from Anywhere: If one alarm detects smoke or dangerous CO levels, all wireless interconnected units will activate, ensuring the earliest possible warning Wide Coverage for Full Home Protection: Up to 24 X-Sense Link+ devices can be interconnected to create a wireless safety network for your entire house 2-in-1 Protection: Equipped with both a photoelectric smoke sensor and an electrochemical CO sensor to provide reliable protection against both smoke and CO Built-In 10-Year Battery: Features a built-in 10-year lithium battery, so you?ll never need to worry about replacing batteries during the lifetime of the unit Informative LCD: Displays real-time CO levels from 30?999 ppm (parts per million) taken from the surrounding air, as well as battery level and working status