Gas Detector, Controller, Transducer, Gas Type C3H8, CH4, H2, Number of Channels 2, Sensor Range 0 to 50 Percent LEL, Resolution 1 Percent LEL, Alarm Type Audible and Visual, Display LED, Status Indicator Yes, Features Powered by Line Voltage, ETL Listed, Supervised System Design, Detector Problem Will Cause the Fan and Alarm Relay to Activate, 5 Year Life, End of Life Indication, Digital Readout Display, Internal Buzzer, Onboard Relays (2), 4-20mA Transduced current loop