The new Perfecto2 W is an ultra quiet version of the Perfecto2. Now, the smallest, lightest, and most energy efficient 5-liter concentrator ever produced by Invacare is also the quietest! Packaged in a contemporary, patient-preferred design, the high-performance Perfecto2 W incorporates all of the great features of the Perfecto2, with added noise reduction to achieve a sound level of just 39 dBa. Also available without the SensO2 oxygen sensor (IRC5PW), the Perfecto2 W represents another quantum leap forward in the evolution of oxygen concentrators.