Aegislink Wireless Interlinked Combination Smoke and Carbon Monoxide Alarm 6 Pk

This combination smoke and carbon monoxide alarm features photoelectric and electrochemical sensors that detect smoke and carbon monoxide, giving you and your family dual protection. The easy-to-read LCD displays the level in real time at CO as well as the battery life, so you are alerted to dangerous CO levels and know when to replace the battery This smoke and carbon monoxide detector has a replaceable lithium battery; the low-battery feature warns you when the battery needs replacing so your home has uninterrupted smoke and CO detection With an open-air transmission range of over 820 ft (250 m).