"The CPAP and BiPAP filters are the perfect accommodation for your ResMed AirSense 10, ResMed AirCurve 10, ResMed S9, and AirStart Series CPAP Standard Machines. They are highly compatible and fit perfectly well with all of the mentioned machines.The product plays a significant role in preventing dirt, dust, or other harmful particles from penetrating the machine. The filter essentially extends the life of your machine and improves your quality of life. The 2-piece premium CPAP filter optimizes air, improves air quality, and allows for easy replacement of the old filter cotton.The filter is made using premium grade materials, that contain no chemical residue and offers a sturdy density, that doesn’t interfere with the air circulation.This is a one-pack filter that is provided to the customers with a minimum warranty and guaranteed after-sales services." Fits seamlessly along with ResMed AirSense 10, AirStart Series CPAP Standard Machines, ResMed AirCurve 10, and ResMed S9. The major purpose of this filter is to keep the air fresh. It recycles the air, removing all the toxins.