I ordered a tower for an Inogen device for a friend and waited forever for it to arrive. I finally gave up and ordered another one from Amazon which arrived in about 2 to 3 days. About a week later my original order from Imogen arrived. I returned it for a refund to Indigent via FedEx ground on June 21 2021. Here is the tracking number: 28-060-3**-**82. As of today (July 8th 2021) I have heard nothing from Imogen nor have I been refunded my money. Inogen makes a semi-good product but their service REALLY STINKS! People who order from Inogen are putting their hopes in a life-or-death product but Inogen's service department is totally incompetent and irresponsible. incompetent an irresponsible. User's recommendation: Buy Oxygen tanks!