Honeywell Analytics SS4-AS2 Multi-Spectrum Electro-Optical Digital Fire & Flame Detector, Aluminum UV/IR, FM, optimised for Non-Hydrocarbons and Silane, Ethanol, Methanol, Hydrogen & Natural Gas Fires, Non-latching Alarm LED, FM, cFM, CSFM for Class I, Div.1 groups B,C & D (2) 3/4 NPT with MA420-4 4-20 mA Module for SS4 Detectors - SS4-AS2-M