Peace be upon you.. Yuwell home oxygen generator model 7F-5. Function: The device works by separating oxygen from the surrounding air and concentrating it at a high percentage to provide respiratory support for the patient. Features: It provides a high oxygen flow of 5 liters/minute. Equipped with a control screen and wheels for easy movement within the home. It has clear buttons and alert lights for ease of use. Used for only two months We ask God for safety and health for all and to heal every patient.