My doctor sent the Rx to Apria, so I used them and I now have 2 big liquid O2 tanks and a small "Companion" that is too heavy for me to carry backpack style and is not intended for that either. It has a shoulder strap but, that doesn't work for my bad shoulder and herniated disc. I love how quiet the LOX is and Helios makes a very small portable called an H300 that I would like to get for buzzing around town. If I give Apria a week or two advance notice they will deliver a LOX tank anywhere in the country. Not too bad for single destination travel. But, for a small travel concentrator they charge a $150 per week rental fee. Ouch! I may look into another provider, possibly Lincare, for a cheaper rental. Skye, I think you lucked out with your company giving you a free one, that sounds like it's unusual. I'm not too happy with Apria, at least here in San Jose, CA. None of them know their products, how to communicate or how to return phone calls and I'm not exaggerating. Isaak in logistics seems to be the sole exception. Sorry, had to vent! I may have to do a combo of LOX and some small backpack size tanks that they can deliver to me. I didn't get the home concentrator because of the noise. Between my neb. compressor and The Vest I think we have too much noise already. I'm new at this and I'm told that I can change my mind later so if my decisions are wrong it's not a problem.