Built upon a legacy of reliable field-proven concentrator models the DeVilbiss 5 Liter Oxygen Concentrator was updated with enhanced quality durability performance and simplicity in mind * Made in the USA this robust oxygen concentrator offers just the right balance of cool and quiet * The simplified two-piece cabinet design allows for 15% typical sound quality improvement and an improved cooling process * Paired with proven exclusive DeVilbiss Turn-Down Technology these improvements minimize wear on internal components and increase the life expectancy of the unit * In fact recent production statistics show a less than 3% warranty return rate * The concentrator is easy to assemble and disassemble and it requires no maintenance for two years * Assorted replacement filters for the Devilbiss 505 515 and 525 Oxygen Concentrators * The 5xx series concentrators use 3 filter types: AIR FILTER 6/PKG (505DZ-604) INTAKE FILTER SILENCER ( 515DZ-605) and FINAL BACTERIA FILTER (PV5LD-651)