MSA, 10080223, Calibration Testing Gas, Type 2AL, Series: Econo-Cal®, Composition: H2S in N2, 40 ppm Concentration, 34 L Cylinder, 13-3/4 x 3 in Cylinder, Aluminum Container, 500 psi Service Pressure, For Use With: ALTAIR® Pro/Maintenance Free H2S Sensor and Gas Detectors, RP Connection, +/-10% Accuracy, Malodorous Gas Odor/Scent