Nuisance free and hassle free 10-year smoke and carbon monoxide alarm. It's two types of protection in one alarm. Featuring a prolonged lifespan of ten years, this model utilizes a ten year sealed battery that ensures a decade's worth of uninterrupted awareness. The 10 year sealed lithium battery, eliminates annoying low battery chirps and costly battery replacements for the 10-year life of the alarm. The PRC710 alarm also adds an element of style to safety with a slimmer round design. Half the size of the standard alarm with all the protection needed to help keep what matters most safe and secure.