The Most Trusted Name In Gas Detection Oxygen (O2) Replacement sensor for the Ventis® Pro Portable Multi-Gas Monitor. The sensor has a measuring range of 0-30% by volume with a .1% by volume resolution. 4 series sensors can be installed in locations 1 or 2 of the Ventis® Pro. This sensor is also available in a DualSense® Technology configuration. Easily replace sensors in the field with little tools needed. 4 Series Sensor |