The Z1™ travel CPAP is the lightest cpap machine available anywhere. At only 10 ounces it is ideal for travel.The Z1 cpap machine only makes 26 dBA of sound during operation. By cpap industry standards that is considered to be exceptionally quiet. In fact, the Z1™ is one of the quietest travel machines on the market.The Z1 cpap system has an optional* integrated battery system that we call the PowerShell™. It delivers a full night of cord-free power on a fully-charged battery. This is a good option for those who travel regularly and must pack light or for those who need CPAP to go with them when plug-in power isn’t available.