The smaller , lighter EverFlo oxygen concentrator from Philips Respironics is making a big impression on providers and patients. Its sleek, ergonomicdesign makes EverFlo easier to store, move, and carry than conventional concentrators. And it is one of the quietest and most energy efficient devices available today .With no filter for patients to maintain, a durable metal oxygen outlet, and fewer moving parts than other concentrators, EverFlo is designed to deliver consistent, trouble-free operation.