Before you buy one of these, make sure you check what else is on the market. These machines are noisey pieces of junk! Even my doctor agreed when I told him. Resmed put this machine out into the market in a hurry! When you complain to Resmed they don't want to know about it!

What I found to improve things was to change from a Activa LT mask to a Fisher & Paykel Mask. That improved things somewhat!