Breas Disposable Filter for Z1 & Z2 Series CPAP MachinesBreas Disposable Filter for Z1 & Z2 Series CPAP Machines: These Disposable Filters from Sunset are designed exclusively for use with Z1 & Z2 Series CPAP Machines. Disposable Filters remove impurities from the air as it is drawn into your CPAP machine to ensure they don't damage you or your CPAP. USAGE: A filter must always be in place when the CPAP machine is in use. For optimal performance these disposable filters should be changed at least once a