O2TOTES USA Premium Ultra Lightweight Backpack fit for the Inogen One G3 Unit (Patented Design) (gray) Fits Units: IS0-300 OR IO-300/NEW IMPROVED DESIGN

Just took delivery on this little O2 concentrator backpack. I am of average height (5'5") but am very, very thin (under 100 lbs). I was worried that I would have to draw the straps in so far to make the backpack fit me that I would have miles and miles of 'extra' strap hanging everywhere. I am very happy to say that there is plenty of strap length so the pack straps can lengthen to fit over bulky clothing/coats but not so much strap that I'm drowning in/tripping over excess strap length when wearing the pack over regular clothing. If you are a larger person, I'm honestly not sure this pack will work for you if need to wear it over bulky clothing. The pack appears very sturdy, and is well sewn. Fits my Inogen G3 perfectly...like a glove (it WILL NOT hold a larger machine). Has a neat little zipper flap thing on the right shoulder strap to help contain/guide your oxygen tubing. It's not terribly obvious in the photos or mentioned in the product description, but this pack DOES have a waist strap (the text on the product photos mentions it). The padding on the shoulder straps is nice and wide. The color of the pack is not a vibrant pink; up close, the fabric actually shows a variegated blend of colors in the weave that from a distance overall reads more towards a light burgundy. It's a lovely color. The pack accommodates an extended battery with ease, and a pad is included to fill the space left over if using a "regular" battery. So far, I am very pleased with this purchase, especially when you see other, supposedly "fancier" packs that are far more expensive with poor ratings. This is a great little pack!

Real nice backpack for the oxygen condenser it also has enough room to store an additional battery makes carrying the machine much easier. My husband has used it while working on his cars and on the farm so that his hands can be free. Very well-made

I had an over-the-shoulder version but due to the weight of the device, if I was out and about for over 4 hours, my back and neck would hurt. So I went for a backpack. It's not as well designed as the other one.If you switch batteries, there's a pad at the bottom that must be removed for the double battery rather than a zipper for expansion like some suitcases.The top is not wide enough to cover the entire width of the G3 device. Also the backpack straps are not centered based on the width of the backpack but based on the off-center top. Regarding the top, the side with the breathing tube protrudes several inches past the strap on that side whereas the other side is almost flush with the edge. Even though the straps are not centered, I haven't felt uncomfortable wearing the backpack.There is a small slit for the breathing tube.There's also a loop to hang the backpack securely on a hook or to use as a handle.There is a hole in the back under the strap for the charging cord but it is not aligned with the port which is close to the top on a G3 device. It makes it awkward to insert the cord.But it is much more comfortable to wear, especially on long walks--no neck and back pain. You do have to buckle the straps in front but that's not a problem. So it does meet my requirement for a more comfortable bag than the over-the-shoulder version for a G3 device.

The backpack fits my one G3 perfectly. I can use my 8hr battery with it and fits perfectly. The chest, waist straps,and tubing holder are easy to negotiate. The best of all is that I can keep the unit on my back while driving around doing errands. The machine works perfectly because there is air around it. AMAZING purchase. Thank you 02Totes

Great item and fits perfectly

I really like this and fits well. Much barry to carry the oxygen portable on my back than my shoulder. A lot more comfortable and I stand up straighter.

I’m 5’4” and weigh 126. The padded part of the shoulder straps could be shorter. The backpack sits right at my waist and the padded strap cuts into my armpits. I can not make the backpack fit better on my back because the padded part is way to long for me. Please consider making a model that fits petite women better. It is made well and light weight.

This makes walking and working easier. Frees up both hands enabling the wearer to utilize both hands for any endeavor. Highly recommend for the active individual.