The " mesh side" is the plastic patterned side. The "felt" side, thus faces out, there's usually a tab that you bend at a 90 degree angle facing out, that's what you pull on to remove it and replace it.
The felt side collects the micro dust from the air as it's sucked thru the plastic cap you fit over the filters. The felt side thus is what you see when checking it for replacement, it becomes gray, not white, if it's black, you waited too long to replace.' I use cpapplus.com for supplies, their filters are cheap, and lightweight tubing, they even have a tube-cleaning brush . And bacterial filters, check those out.
Slo- I'm using the same gear. I've used the Mirage Swift I, II, and LT, and now the FX. Chinstraps are hard to get right- this is the best I've found so far- fyi-
https://www.cpap.com/productpage/cardin ... strap.html