Hardwired Smoke & Carbon Monoxide Detector, 10-Year Battery Backup, Voice Alerts, Interconnectable LED Warning Light Indicators, 4 Pack

2-IN-1 DETECTION: Alerts you to both smoke and carbon monoxide (CO) with a single, economical device. HARDWIRED & 10-YEAR POWER: Functions on 120V AC wiring (installed in the ceiling). No battery replacement is needed for 10 years. ENHANCED SENSING TECHNOLOGY: Minimizes false smoke alarms frequently triggered by cooking. Thoroughly tested to comply with the latest UL standards, including UL 217 9th Edition, UL 2034 4th Edition, and FCC standards. VOICE ALERTS: Clear voice alerts will announce "Fire!" when smoke is detected or "Warning! Carbon Monoxide!" if CO is detected, enabling a swift response. INTERCONNECT CAPABILITY: When one alarm activates, all interconnected alarms sound, allowing for a quicker exit. Different models provide different interconnection options and requirements. Consult the User Guide for further details