Check the listing for details. SYSTEM SENSOR- SERIES SMOKE DETECTOR. Condition: Used. Listed at 25.00 USD. This System Sensor smoke detector is a reliable and effective tool for fire protection in any facility. Made by a trusted brand in the industry, this smoke detector is designed specifically for detecting smoke and raising alarms in case of a potential fire hazard. It is perfect for use in a variety of settings, from homes to large office buildings. With its advanced technology and high-quality construction, this smoke detector is a must-have for anyone looking to ensure the safety and security of their property.