Onelink Wi-Fi Smoke + Carbon Monoxide Alarm, Hardwired, Apple HomeKit-enabled Combination smoke detector/carbon monoxide alarm detects two threats HomeKit-enabled to send notifications to your Apple device (requires iOS 9.0 or later) Hardwired design can replace most 120-volt AC hardwired alarms with no rewiring 10-year sealed battery helps ensure consistent protection with no need to replace battery Multiple alarms can communicate via Bluetooth and announce audibly where and what the threat is