My husband and I would like to purchase one from you. We are in our 70s and heart patients at Mayo. We live in CA now and are on a waiting list to move to Charter House. We have been housebound since Feb. We cannot fly to get our tests which were due last June. My heart problem is an ascending aortic aneurysm of at least 4.7 as of last Dec. We would gladly pay double for quality masks. There are so many out there and it is confusing. Thank you for your consideration.