Pulse oximetry is used to continuously and noninvasively measure functional oxygen saturation in the blood. The pulse oximetry sensor contains two infrared light-emitting diodes (LEDs) and a photo detector to measure how the amount of light absorbed by the arteriolar bed varies during pulsations. The SpO2 sensor is also used to continuously and noninvasively measure pulse rate. The monitor displays this functional oxygen saturation as percent SpO2. When ordering the Command Module, you have a choice of SpO2 technologies: Spacelabs, Masimo SET, or Nellcor OxiMax. Spacelabs distributes the SpO2 cables, reusable and disposable sensors you need to operate your Spacelabs legacy or current production patient monitoring system.