I purchased one of their units and O boy what a ripoff I purchased one of their units, after I received it I tried it and realized it was not going to work for me. Since the unit had a 30 day return policy for a full refund, I started trying to call their listed customer service number and found out later in an email that their phone number wasn't working! Then after 9 emails they finally gave me a Rma number and the shipping address that was in China I attached a label and took to UPS where I was told it would cost 400 to 500 dollars to ship it to China which exceeded the purchase price of 351.10. So it's a ripoff if you ever need to return it for credit or service!! What a rip-off!!! BUYERS BEWARE !!

It's easy to use, and I can go out easily. I purchased my own unit about 2 months ago, and I absolutely love it. I also got an extra battery for peace of mind. It's so convenient to switch to the spare battery when the first one runs out, and it only takes seconds. This device has made it much easier for people like me who had difficulty getting out in the past.

Thank you for resolving the delivery… Thank you for resolving the delivery issue with the portable concentrator battery. After the first one got lost in transit, you promptly sent a replacement, which works perfectly. I would recommend your company to anyone in need of oxygen therapy.

I bought the 3-liter continuous flow… I bought the 3-liter continuous flow machine less than a month ago, and so far, it's been great. It was well-packaged and is functioning perfectly.

So far So far, so good! I've only had the unit for 4 days, but it seems to be working well. A friend of mine wants to order the same NT-03 model, and I might gift one to him for being such a helpful friend. I'll need more information from him to confirm if this is the model he wants.