DESC: #900-0102 The Kidde KN-COSM-B Combination Carbon Monoxide Smoke Alarm provides two important safety devices in a single unit. This alarm includes a voice warning system that announces Fire, Carbon Monoxide, Low Battery or Smart Hush Activation. The voice alarm eliminates any confusion and clearly warns you and your family of a smoke or carbon monoxide danger, or if your battery is in need of replacement.