Now there is one economical instrument that reports all the operating parameters necessary for performing concentrator checks. Introducing the Check O2 Plus an efficient and cost-effective analyzer designed with technicians in mind. It checks oxygen purity (percentage) flow rate (up to 6 LPM) and patient outlet pressure (psi-kPa) on any oxygen concentrator. In addition the unit never needs to be calibrated and there is no fuel cell to replace. The Check O2 Plus is three analyzers rolled into one Features: Simple two button operation with a 9-volt battery power source - provides three years of typical use. Shuts off automatically to extend battery life. Never needs to be calibrated Measures three parameters eliminating the need for multiple instruments. Never needs to have the fuel cell replaced with its ultrasonic technology