Product Description Industrial Scientific Ventis MX4 O2 Oxygen Sensor, Measuring Range: 0-30% of vol. in 0.1% increments (Also fits older model MX4 iQuad Gas Detectors)Has your O2 sensor failed or has a measuring range that's all over the place? It might be time to replace it. Repair your Industrial Scientific MX4 Multi-Gas monitor by purchasing a new genuine Industrial Scientific (O2) Oxygen Sensor.Need some DIY help changing a sensor or just some friendly technical help with repairing your instrument? Call customer service at 1-800-949-7233. You can buy with confidence because Durawear has quick shipping and free technical support to help you install your new Ventis MX4 Oxygen Sensor. Also the sensors we sell are always fresh from the factory, no need to worry about getting a sensor that has been sitting on our shelf for a long time. Reviews 4 O2 senser Posted by Unknown on Aug 29th 2016 Everything was quick and simple . The Product was on the shelf and ready to ship.