The inline filter is suitable for CPAP devices. It is used in combination with the machine's built-in inlet filter to deliver clean air. The outer diameter of the connector end: 25mm. The inner diameter of the female connector end: 22mm. Compatible with 22mm tubing. Installation and replacement are quick and easy. The filter is connected between the air inlet or outlet of the machine and the hose. Best Results: Helps maintain clean air intake for optimal CPAP therapy performance. Includes 6 filters. Latex-free. Each filter is individually sealed. Material: ABS Color: As shown Package Contents: 6 x Filters Only the above package content; other products are not included. Note: Lighting and monitor settings may cause slight color variations between the image and the actual item. Measurement allowance: +/- 1-3cm.