In compliance with FDA requlations, DirectHomeMedical requires a prescription for selected items sold on this site including CPAP & BiLevel Machines, CPAP Masks, Humidifiers, Oxygen Concentrators, and selected other items. Concentrator, 8 cells Battery AC Power Supply DC Power Cable Carry Bag User Manual Compact and Lightweight Flow Settings 1-6 Intelligent Pulse Oxygen Delivery Designed for 24 Hour Use Easy to read LCD display Inogen Connect App