Breas Disposable Filter for Z1 & Z2 Series CPAP Machines:
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 month or sooner if they appear soiled or discolored. For complete instructions review the documentation that came with your equipment.
DIMENSIONS: 3.5 x 2.0 x 2.0 Inches