An efficient and cost-effective analyzer designed with technicians in mind. It checks oxygen concentration (%), flow rate(L/min), and patient outlet pressure (psi/kPa) on any oxygen concentrator. Never needs to be calibrated, and there's no fuel cell to replace. Features simple, two button operation. 9-volt battery power source provide three years of typical use. Shuts off automatically to extend battery life. + -2% accuracy oxygen percentage between 73.0-95.6% range. Weighs 10 oz. 2-year limited warranty.