Stroller, carry set or portable: A so called stroller, carry set or portable is a handy device with a shoulder strap that can be filled on the l liquid oxygen vessel. Such units are available in various sizes and there is a top fill and side fill variant. It can vary per country or even state what type of liquid oxygen base unit/vessel is available. If one intends to bring his or her own portable device to the holiday destination it is advisable to check with OxygenWorldwide on forehand if the equipment will be compatible.