ACI B5-H2-1000P-O-X : Hydrogen Toxic MS/TP BACnet Gas Detection Transmitter, 0 - 1000 PPM, -4 to 122 Deg F(-20 to 50 C), 7500 sq. ft (696.7 sq. m), 49 ft radius(14.9 m), Relay, LCD Display, 0.5 to 1.5' (0.15 to 0.46m) Below Ceiling Mounting Height, 2-Year Warranty, Made in USA