The inline filter is suitable for CPAP devices. It is used in combination with the machine's -in inlet filter to deliver very clean .The outer diameter of the connector end: 25mm. The inner diameter of the female connector end: 22 mm. Suitable for 22 mm pipe making machine.Installation and replacement are quick and easy. The filter is connected between the or outlet of the machine and the .Best Results: Keep the inhaled by the CPAP machine clean for the best therapeutic effect.A set of 6 filters. Does not contain . Each filter is individually and sealed.Material:ABScolour:As ShownPackage Contents:6 x filtersOnly the above package content, other products are not included.Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.