The purpose of this study is to evaluate the long-term durability of the treatment and safety of the Provent device for those individuals who were enrolled in the C009 study, were diagnosed with obstructive sleep apnea-hypopnea (OSAH), and were actively using the Provent device.

Inclusion Criteria:

1. Based upon scoring at the study site, the 3-month 'device on' PSG has a 50% reduction in AHI compared to the 1-week 'device off' PSG AHI OR the 3-month 'device on' PSG AHI <10
2. Used the Provent device at least 4 hours for at least 5/7 nights per week on average during months 1 and 2 of the three month C009 study
3. The study physician and investigator believe that continued Provent use does not represent a significant safety risk for the patient
4. Patient understands and is willing and able to comply with study requirements

Exclusion Criteria:

1. The patient must continue to not meet all of the exclusion criteria of protocol C009

OSA subjects from C009 AERO study who were randomized to the Provent arm and completed the study. All must continue to meet the C009 inclusion and exclusion criteria.