The filters are indeed the most basic quality. I would be happier paying a reasonable additional amount for a more satisfactory filter with a better fit. These will do until I need more and pay more, I'm sure worth the satisfaction.
My husband has stage 4 thoat cancer and had a larengetomy and now breaths through a hole in his neck so clean air is a must. We have a weird size filter and this fits perfect and works great. Thank you