I have 3 ex-15 oxygen concentrators for sale. All work great and are less than a year old. I have changed the filters twice on each one. Purchased from Abr imagery. I do have reciepts somewhere. I switched to liquid so i need to get these out of my shop. I am in Northern California ( lake/ Mendo ). For pick up only. I will not ship! 707 413 3160. I have no answering machine on this phone, so if i dont answer... call back! Thanks