Check the listing for details. Welch Allyn Protocol Mainstream CO2 Sensor 108-0502-00. Condition: Used. Listed at 189.95 USD. Welch Allyn Protocol Mainstream CO2 Sensor 108-0502-00 New old stockListing is for ONE unit. Two shown for reference. E-bay Required Medical Disclaimer: By purchasing, buyer is stating they are not prohibited from purchase, ownership, or possession of item. Buyer attests they are a physician, licensed healthcare practitioner, or any other practitioner licensed by the law of the State in which the practitioner practices to use or order the use of the device."The sale of this item may be subject to regulation by the U.S. Food and Drug Administration and state and local regulatory agencies. If so, do not bid on this item unless you are an authorized purchaser. If the item is subject to FDA regulation, I will verify your status as an authorized purchaser of this item before shipping of the item."Dalma CorpNew Orleans, LA800 816 9858 Listing and template services provided by inkFrog