Inogen One G4 Portable Oxygen Concentrator vs Inogen One G3

Both are Inogen pulse-dose portables with a 3-year warranty. The G4 is the pick for mobility: at 2.8 lbs it is the lightest Inogen and easy to carry, but it tops out at flow setting 3 and its single battery runs about 2.7 hours. The G3 weighs 4.8 lbs and gives you five settings, a 90% concentration spec, a longer single-battery run and a quieter 39 dBA rating, so it suits higher oxygen needs and longer days out. Owners praise the G4's weight; some find its motor and pulse bursts louder than expected.

• Choose the Inogen One G4 if you want the lightest Inogen to carry on errands and short trips and your prescription is flow setting 3 or lower.
• Choose the Inogen One G3 if you need flow settings up to 5, longer battery time or a quieter unit, and can carry a few extra pounds.