These really work well in removing impurities that get though ...
These really work well in removing impurities that get though the CPAP's external filter.  I use the same criteria in changing this as I do for the machine filter.  It is installed in the hose that connects to your mask.  You can purchase these in lots of 50 which greatly reduce the single unit cost. I feel it is well worth it to add another layer of filtration that my lungs don't have to deal with.
Rating: 5 stars