Resmed Airsense 9 (S9) Elite CPAP Machine with H5i Humidifier - 36013Resmed Airsense 9 (S9) Elite CPAP Machine with H5i Humidifier 36013 Condition: We have lightly used with under 1000 hours(used less than 4 months). And we have very used with 1k 15k hours. Machines can last 30k hours which is 10 years. Also, we have very used machines without the humidifier. If you are looking for a good CPAP machine that works just as good as the most modern models and is less expensive, then this machine is your best option.