@gramps Hello! I don't even know 🙁 I have a Phillips Respironics Auto CPAP 500X110. But I am trying the two different mask they sent me home with. I need to see which one works best before the tech sends in for supplies. This way my insurance will cover. Last night was not good. I took mask off after an hour use. My nose was so dry. When I imported my data it said I had major leakage 95%!!!! And this is the mask that I liked 🙁 Oh boy. I am going to try the other mask tonight.