Just like the Nonin Onyx 9500, the Onyx II 9550 is designed to take the abuse of cockpit and general travel. However, the 9550 adds some important upgrades that make it the best fingertip pulse oximeter currently available. An internal clip spring, built-in gripping insert and easier to open battery door make the 9550 easier to use and maintain over the 9500. Unlike the cheap units found in drugstores, the Nonin 9550 is designed for clinical, MEDEVAC and EMT use. This translates into years of reliable oxygen saturation statistics even under heavy use. For pilots frequently flying at high altitudes, the 9550 is a perfect choice to help protect you against in-flight hypoxia.
