Battery powered smoke/carbon monoxide combo alarm, 9v battery powered, electrochemical carbon monoxide sensor, 2 latching features: alarm latch to easily identify initiating alarm after alarm condition has subsided, low battery latch to visually identify which unit is in low battery condition, 2 silence features: alarm silence to temporarily silence nuisance alarms, low battery silence to silence low battery chirp for up to 8 hours, intelligent sensing technology helps reduce the number of nuisance alarms, perfect mount allows for easy alignment of alarm, dust cover, includes mounting anchors & screws, single button test, 10 year limited warranty, note: please check your local building code requirements before installing this product to determine compliance with applicable standards.