Stay away from these guys! Sales and customer service tells different stories, starting with them sending a unit I really didn't want. I use a walker and this machine is set inside its own roller walker. That would be interesting to get around with. Sales said I had 30 days to return it but customer service says there is a fee of 25 after 5 days. But today I find out it's 25% plus shipping - delivery and return. Cost back to me is over $800 which is outrageous. Live on Social Security, like many others using oxygen. Beyond Disappointed