The System utilizes oxygen generation method know as the PSA (Pressure Swing Absorption) system. It is a self-contained system for the production of high concentration oxygen, using a unique material called Molecular Sieve to separate the oxygen from the nitrogen in the ambient air. Nitrogen is ejected and oxygen is concentrated and redirected for use. Oxygen concentration in ambient air is approximately 21%. Oxygen concentration from a PSA system is approximately 92% plus or minus 3% (industry standard). SPECIFICATIONS Oxygen Output 5 LPM (litres per minute) Oxygen Output 92% plus or minus 3% Response Time 5 minutes to attain maximum purity after initial startup or extended shutdown . Dimensions ~350Wide × 420Long × 650High Weight 41.2 LB (21.0 Kg) Power Requirements 220 VAC, 50Hz, 3.5 amps