Winix Filter H Cassette for 2020EU Air Purifier, 77 Litre - white/black

It doesn't capture ultrafine (.003 microns) dust. It's holding it for 2-3 days and blowing it back into the air which causing me difficulty in breathing. I have to vacuum clean it every 2-3 days to refresh the filter. So much of a hassle.I don't have a choice but to try IQAir and it really worked perfectly. It is expensive but it is the only air purifier that can capture ultra fine dust (.003 microns) and hold it in the filter forever. No Air Doctor, No Philips. I have tried them all and they all have the same issues. Coway doesn't capture .003 microns particles. However, their OEM filters comes with the unit is working but not their OEM replacement filter. So it is unreliable.