Product Description Replacement electrochemical Carbon Monoxide and Hydrogen Sulfide sensor for the Ventis® Pro. The CO/H2S sensor is a single sensor that can detect both Carbon Monoxide (CO) and Hydrogen Sulfide (H2S). The CO/H2S sensor has a CO measuring range of 0-1500ppm with a 1ppm resolution and an H2S measuring range of 0-500ppm with a .1ppm resolution. This 4 series senor is only available for the Ventis Pro 5, and can be installed in locations 1 or 2. (This sensor will not fit or work with Ventis MX4 Series Gas Monitors)Has your COSH sensor failed or has a measuring range that's all over the place? It might be time to replace it. Repair your Industrial Scientific Ventis Pro Multi-Gas monitor by purchasing a new genuine Industrial Scientific (COSH) Carbon Monoxide / Hydrogen Sulfide 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.