San Antonio Express-News, Price: $350.00, Product ID 1020001 has 562 hours Excellent condition The EverFlo Q Respironics Oxygen Concentrator is Stationary, Compact at 31 lbs. and Low Maintenance! Ultra Quiet The Respironics EverFlo Oxygen Concentrator is a 5 liter per minute stationary oxygen concentrator. Uses less power and produces less heat, so concentrator is more patient friendly. No filters for the patient to change! Send a message if you are interested