Gas Detector Sensor, Gas Detected Carbon Monoxide, Hydrogen, Hydrogen Sulfide, Measurement Range Cobalt Hydride (0 to 2, 000 ppm), Hydrogen Sulfide (0 to 200 ppm), Compatible Detector Model/Series ALTAIR 4XR, ALTAIR 5X, Compatible Detector Grainger Part Number 45KE54, 45KE55, 481P57, Sensor Type Catalytic, For Detector Type Portable, T90 Response Time 15 sec, Sensor Life 4 yr, Series ALTAIR 4XR, ALTAIR 5X, Features Quick Response Time, Resolution Carbon Monoxide 1 ppm, Hydrogen Sulfide 0.1 ppm. This item has been restricted from sale in the following state (s): []