A portable oxygen concentrator from the GCE Zen-O model. New, only used for one month.. It provides oxygen in two modes: pulse flow (up to setting 6) and continuous flow (up to 2 liters per minute). It runs on rechargeable lithium-ion batteries and can operate for up to 8 hours in pulse mode. It is lightweight (approximately 4.66 kg) and suitable for use on the go or while traveling. Approved by the US Federal Aviation Administration (FAA) for in-flight use. It features technology that senses breathing rate and automatically adjusts oxygen flow to meet the patient's needs. __________ Price: Highest offer