The S Series multi-criteria photoelectric smoke alarms are for use as evacuation devices in all dwelling units, including but not limited to homes, apartments, hospitals, hotels and motels. Available in several different models, the S Series is engineered to virtually eliminate nuisance alarms and deliver outstanding performance wherever reliable fire protection is required. The S Series is available in 120VAC and 220VAC (selected models), all with 9V alkaline battery for back-up in the event building power is lost. Options include self-restoring 135F integral (STRR) and isolated thermals (SHRR) with rate of rise and Form A/Form C dry contacts for remote annunciation.