The SeQual Eclipse 5 is the newest and most improved upon in the Eclipse line by SeQual. It has the same great features, oxygen settings and battery life as the Eclipse 3, only with better overall power and the ability to run on DC power and charge at the same time. If you are looking to get an Eclipse, this would be the one to get. This is a portable oxygen concentrator that provides a wide range of both continuous flow and pulse dose oxygen settings.