Philips Respironics Ultra Fine Disposable Filters come in a convenient pack of 6 and are used with the System One CPAP or Bi-PAP Machines. They can also be used with M-series CPAP or Bi-PAP Machines as well as Sleep Easy CPAP Machines. Have over 40 in stock. Selling these in a pack of 10. CPAP America is your one-stop-shop for all of your sleep apnea needs!