For sale: Yuwell oxygen concentrator device, model 8F-5A, in excellent condition and working efficiently. Specifications: * Oxygen flow from 0.5 to 5 liters/minute. * Oxygen concentration up to 95.5%. * Suitable for home or medical use as prescribed by a doctor. * Quiet during operation. * Equipped with a humidifier bottle and oxygen tube. * Easy to use and move. Condition: * The device is working properly. * Reason for selling: No longer needed Note that the original price exceeds 4000.