Specialty-Medical.com carries the top oxygen concentrators in the medical industry. The Invacare oxygen concentrators and the Devilbiss oxygen concentrators have proved to be the most reliable and most economical backed by the best warranties in the industry. Unlike some of the other oxygen concentrator companies, Invacare and Devilbiss have one of the largest dealer networks in the country which makes it a lot easier after the purchase to find qualified service technicians to service or repair your oxygen concentrator. The Invacare Perfecto2 5-Liter Oxygen Concentrator, the newest in the Invacare line is a quantum leap forward in Oxygen Concentrator design featuring a smaller size; quieter concentrator motor; available with or without oxygen sensor. See our oxygen concentrator tips page for more information and reviews.