The Mars Wellness CPAP Filters are a great option for sleep therapy users who are prone to sickness or allergies. They actively clean the air as it leaves your CPAP or BiPAP machine, working in conjunction with the machine's built in filters, to provide exceptionally clean air throughout the night. The Mars Wellness Inline Filter Kit with multiple connections allows for a more varied and open use. The included adaptor kit includes adaptors of 22MM outer diameter to 22MM inner diameter. 15MM outer diameter to 22MM inner diameter. 22MM outer diameter to 22MM outer diameter and a 22MM outer diameter to a 22MM outer diameter with a 15MM inner diameter. These special connections allow you to use your inline filter with all machines makes and models, with all variation tubing.