Metal o2 outlet & 2 separate filters prevent dirt, dust, and lint from entering adding to the life of this unit. & Indicator lights notify users of pressure, flow, and oxygen irregularities. Oxygen Purity: 95%-87% at all flow rates. Flow Range: 0.5-5 LPM. Quiet, w/four rolling castors allow for easy transport. 3 year warranty. #10800-Each UNSPSC#42272202