The 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 connector end: 25 mm. The inner diameter of the connector end: 22 mm. Suitable for 22 mm hose making machine. Installation and replacement are quick and easy. The filter is connected between the air or machine outlet and the CPAP hose. Best results: Keep the air inhaled by the CPAP machine clean for the best therapeutic effect. 24 filters. Does not contain latex. Each filter is individually sterilized and sealed. Material: ABS Color: as shown Package Contents: 24 x Filters Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in a little different from the real thing. The measurement allowed error is +/- 1-3 cm.