INOGEN One G5 Portable Oxygen Concentrator. Also included AC power supply with power cord, DC mobile charger, external Battery charger, carrying case, lithium ion 8-cell battery, lithium ion 16 -cell battery(never used), cannula and manual. Purchased at the end of Sept.2021. Very lightly used . Value $4000 Asking price $2200 Call 808-334-0151