If I could give less than one star I would. They sent a tech who had never done the repair necessary for my dad's concentrator. Also sent her with no tools for the repair. My elderly father read the instructions and provided her the necessary equipment to fix it. His mobile unit needed a repair. The substitute unit was supposed to last four hours and it lasted one. He ran out of air while doing errands. The substitute's replacement did the same thing. One hour!! These are just a few of the dangerous practices this company has done in the last three weeks. They take forever to fix anything. Shoddy equipment. Terrible company who does not care about sick people. Go elsewhere.