This is the replacement foam pre-inlet filter for the Respironics Millenium oxygen concentrator made by Sunset Healthcare Solutions. This is a direct replacement for Respironics part #H618
The foam pre-filter is installed inside of the cabinet on the Millenium 5 & 10 liter oxygen concentrators. The foam pre-filter is typically installed on the inlet side of the plastic cartidge HEPA filter. The filter measures 2 1/2 inches in diameter and 2 1/2 inches tall. There is a 3/4 inch opening on the bottom of the filter so it can be attached to the inlet side of the cartridge type HEPA filter.
The the foam pre-filter are accessed by removing the panel cover on the back of the unit. Pk/1