(5 out of 5) by Robert R, Kingston, MA

"they do not work in overly dusty hotel rooms, large hotel rooms in example. they work best when air purifiers are in use in the room however, i continue to have minor and mild dust allergy attacks and if they continue i will have major surgery to correct the sleep apnea instead of using the machine. some one need to make a machine that stops dust, dust mites and all other crap in the air from getting in the machine and into the patients sinus"

(3 out of 5) by Roger

"After using the filter for a few weeks I believe that the quality of air is a little better resulting in less head-stuffieness upon awaking. So basically I am satisified with the filter as I have the same refreshed and ready to go feeling when I get up. I have noticed, however, that when the CPAP machine is turned on there is s new wheezing sound which seems to imply some air restriction. I now have some concerns about receiving the correct air pressure or wondering if the machine will wear out more quickly."

(5 out of 5) by Robert W, Ermington NSW, --

"Works with my Respironics M Series on auto setting, although for some reason on the first night only it did not log the hours used. Been fine since then. It immediately restored my hayfever from intolerable to the usual very mild. I am surprised they are not suggested as a standard accessory and that I had to buy one from the other side of the world after deciding to look for something like this."