X-Sense XP04 AC Hardwired Combination Smoke and Carbon Monoxide Alarm 3-Pack

AC Hardwired. Hardwired Interconnected Alarm. Indicator Light. 120 V AC (60 Hz, 45 mA MAX, and 9 V alkaline battery backup). Alarm Noise Level. ≥ 85 dB at 10 ft (3 m) @ 3.2 ± 0.3 kHz pulsing alarm. 1 × Alarm Unit + 1 × Mounting Bracket + 4 × Screws + 4 × Anchor Plugs + 1 × 9 V Battery + 1 × Power Connector + 1 × User Manual.