The Kidde P4010DCSCO-W is a reliable smoke and carbon monoxide alarm dated 9/2023. It ensures the safety of your home with advanced detection technology. 10-Year Sealed Lithium Battery: Eliminates late night battery chirp Voice Notifications Bug Screen: Protects alarm from insect ingress Flashing LED Status Ring: Allows easy identification of current state of alarm Supervised Wire-Free Interconnect: Proprietary radio signal joins multiple alarms together, so when one alarm sounds they all sound. User is alerted if an alarm loses connection to the network. Sealed-in Lithium Battery: No battery replacement required over the 10 year life of the alarm. Eliminates worry about battery removal or unauthorized deactivation of alarm. Compatible with RemoteLync Bridge: Connect to the Kidde app for additional features and benefits. End of Unit Life Warning: Alerts user the alarm is in need of replacement. Test / Hush® Button: Tests alarm circuitry and activates Hush® feature to temporarily silence nuisance alarms for up to 10 minutes. End of Unit Life and Network Error chirps can also be silenced. Alarm Locate Feature: Quickly find initiating alarm by silencing other alarms in the network. Ambient Light Sensing: Establishes Day/Night cycle and prevents chirping during the night until the next Day cycle begins. Intelligent Sensor Technology: Reduces nuisance alarms and offers fast response to real fires.