For sale- an Inogen One G5 portable oxygen concentrator. Unit is in very good condition, clean and ready to use. Only 688 hours on it. Includes carrying bag, backpack carrying bag, instruction manual, and two batteries. The larger extended battery works perfectly, the smaller standard battery is defective- charges sometimes, does not work consistently. These units sell for $3000 new. This one is only $1000 cash. Let me know if you want to come check it out.