Honeywell XCD Sensepoint Gas Detector, Hydrogen (H2) Electrochemical Sensor with aluminium housing (optional stainless steel), stainless steel sensor head, explosion-proof IP66 for hydrogen (H2) 3-wire 24 VDC power, include 2 programmable alarm relays, 1 programmable fault relay, 4-20mA output (sink or source selectable); Modbus RTU option available. User-Selectable full scale range 1,000ppm only UL/CSA Class I Division 1 or ATEX IECEx available.