Arman knows his shyte! This man lives and breaths CPAP machines. Not only does he sell product and equipment but he also wears a CPAP. So he can easily guide you to the proper piece of equipment that not only suites your needs but also to provide you with the ultimate best nights sleep. He gives you the right answer to your question, very very knowledgeable without using a book. All of his experience comes from first hand knowledge. So if you are visiting Las Vegas or if you live here, this is the place to go for all of your CPAP NEEDS. BTW he even ships supplies too. I am now a customer for life!