Note: these machines make their own oxygen. Oxygen tanks are not required. Only the rear air filter needs to be cleaned once in a while. Simply plug it in, turn it on and in 5 min the unit produces 93% oxygen for years and years!
AirSep New Life Intensity Oxygen Concentrator 10 LPM NEW
Altitude Tech Oxygen Concentrator - Altitude Trainer Dual Contrast
Invacare Perfecto2 Oxygen Concentrator 5LPM REFURBISHED
Invacare Platinum 10 LPM Oxygen Concentrator
Oxygen Tech 10 LPM Oxygen Concentrator w/ HEPA Filtration
Respironics EverFlo Oxygen Concentrator 5LPM Refurbished