Best Inogen portable oxygen concentrators

Top pick: Inogen Rove 6. It's the newest and most flexible of the Inogen line — six pulse-dose settings, and it's the lightest way to get that much range, at about 4.8 lbs with the standard battery (5.8 lbs with the extended one). Best if you're active, travel often, or your prescription needs higher settings.

Who the others suit:

• Rove 4 — the same idea with four settings and a very light body; good if your needs sit at the lower end and you want the simplest carry.
• Inogen One G5 — six settings and a strong track record with users; a solid all-rounder if you don't need the newest model.
• Inogen One G3 — older and heavier, but a proven, straightforward unit for lighter use.
• Inogen One G4 — the smallest of the One series; pick it only if size matters more than settings.
• Inogen At Home — not portable: a stationary unit for overnight or high-flow use at home, often paired with a portable.

All the Inogens here are pulse-dose; if your doctor prescribed continuous flow, the CAIRE Eclipse 5 is the one to look at instead.