Honeywell Home V-Plex Addressable Photoelectric Smoke Detectors are designed to provide open area protection and to be used with compatible UL or ULC-listed Honeywell Home control panels that support V-Plex technology. The detectors incorporate a state-of-the-art optical sensing chamber and an advanced microprocessor. Built-in Drift Compensation algorithms automatically maintain proper operation at factory calibrated detection levels, even when sensitivity is altered due to the presence of contaminates settling into the unit’s chamber. The 5193SDT also features a restorable, built-in, fixed temperature (135°F/57.2°C) thermal detector.