OMS Professional Diving Oxygen Analyzer specifically engineered for analysis of scuba diving gases. This analyzer has seen only limited use and is in excellent condition. Originally sold for $350.00. The analyzer has a new 12 volt battery but will require a replacement oxygen sensing element (these need to be replaced every few years). Oxygen sensing elements were manufactured for OMS by Analytical Industries, Inc. (Model PSR-11-39-MD5) and are readily available from Dive Gear Express Pompano Beach, FL (866)498-6857.