Freedom V² CPAP Battery Kit for ResMed S9 Series 18" wheelchair The stool features a padded Size:10 Ft The stool features a padded seat and back for added comfort and an angled seat that makes sitting down and getting up easy 000 ft FAA Approved Yes FAA approved label visible on device Oxygen Concentration Purity 90% 3% +6% at all settings Warranty 2 Years (1 Year on Pre Owned Units) *after 500 cycles the battery shall recover at least 70% of its initial charge Weight: 1 Unique variable voltage design and smart DC cables with dynamic control output make the Freedom V2 an industry leader in CPAP travel battery and backup power supply technology