Portable Oxygen For The Way You Want to Live The ALL-NEW Includes Everything You Need To Regain Your Freedom Meets FAA Requirements for Travel Portable Oxygen That Will Never Weigh You Down. At just 2.8 lbs, the Inogen One G4 is the ultralight portable oxygen concentrator you have been waiting for. The Inogen One G4 is approximately half the size of the Inogen One G3. JUST 2.8 LBS! Actual size: L 5.91" x W 2.68" x H 7.2" REQUEST YOUR FREE INFORMATION KIT TODAY. CALL NOW! 1-800-519-4605 © 2017 Inogen, Inc. All rights reserved. M ADE IN TH E US A MKT-P0055