Thanks again Pugsy.

ChicagoGranny and Pugsy...thanks for your replies and the links. I think I will try an order the clinician manual as you suggested. I think you would both agree that the description in the user manual makes it sound like FLEX and Mask (System One) setting are the same thing. The user manual says: FL...

The Phillips Dream Station has a FLEX setting and Mask setting (System One setting). According to the manual they both seem to control the same thing. The FLEX setting cannot be turned OFF. You can set it to 1, 2 or 3. The Mask (System One) setting can be turned OFF or set to the System One setting ...