Oxygen concentrator portable rental: More and more people travel with rented portable oxygen concentrators. Rented or not a portable oxygen concentrator is a very sensitive device and can easily break down. If this happens not many rental comapnies will be able to assist you immediately. OxygenWorldwide in most cases can by means of their S.O.S. Back-up service. It is advisable to pre-register when you start to travel with a portable oxygen concentrator so you know what back-up possibilities there are at your destinations.