Top critical review
Thick material, partial vent coverage, doesn't help complete air clean-up
18 October 2018
PS - Check AliExpress for a better price.
The material of the filter is thick. It has perforations within centimetres across its stretch and has threads woven across to capture the smallest dirt particles, which implies lesser air flow through it(the mesh itself). As the description says, the length of the material is not enough to capture the entire filter and hence the side-areas of the original ac filter are left uncovered. First - The claim of 80% clean Air within the first hour doesn't work. Second - the dust on the side-filters eventually enters the air atmosphere and spoils air-quality. In comparison, I tried to cover the entire ac filter with another cloth and had much lesser dust floating around and much lesser nasal problems while breathing.
I would recommend 3M to reduce thickness of the filter with more uneven perforations and increased length to cover the entire filter. That'd be a great design and would really be helpful in capturing all dust in one go. never killed to have a washable material either. consumers like that.