Built to withstand tough environments, MSA's Orion® Multigas Detector for O2, H2S, CO, and combustible gas is low-cost, reliable, and easy to use. The handheld Orion Detector, with MSA's long-life 20L combustible sensor and many component choices, is custom-assembled to your needs. With one-button calibration, carbon-filled nylon case, built-in pump, durable sensors.