This spring, my beloved dog was diagnosed with pulmonary edema. He was in and out of the hospital's oxygen chamber and used it at home for treatment. He was able to breathe easier when using it with his special cage. It really helped him. Unfortunately, he crossed the rainbow bridge this month. It has been used for 1132 hours, but there are new filters, so it can still be used. I would like to offer it to someone who needs it. Product Description Purchased on Amazon on May 24, 2025. Used for 1132 hours.