Voice messages identify different dangers. Hush button quickly silences nuisance alarms. Test/Rest button tests circuitry and resets alarm. The Talking Combination Smoke & CO Alarms is a 2-In-1 Unit constructed to detect both smoke and carbon monoxide from any source of combustion in a residential environment. Equipped with Hush® and and Test/reset buttons, this alarm is designed to identify different dangers and also sensitive to fast flaming and other fires. Features: • Ionization Technology – Better at detecting fast flaming fires. • 120V AC Direct-Wire – Interconnects with up to 24 units, of which 18 can be initiating. • Test / Reset Button – Tests circuitry and resets alarm. • Hush® Button – Quickly silences nuisance alarms. • Talking Alarm – Voice messages with sounding alarm identify different dangers. • 2-in-1 unit – Advanced sensors for detecting both CO and smoke.