Features: OOTDTY new and high quality The inline filter is suitable for CPAP machines. It is used in combination with the machine's built-in inlet filter to provide very clean air. The outer diameter of the male 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 between the air or outlet of the machine and the CPAP hose. Best results: Keep the air inhaled by the CPAP device clean to get the best therapeutic effect. A set of 6 filters. Does not contain latex. Each filter is individually sterilized and sealed. Specifications: Material: ABS Weight: 30g Size: As picture shows Package Includes: 6x Inline CPAP Filters Note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. 2.Due to the difference between different monitors, the picture may not reflect the actual color of the item.