I have been using your filter for two weeks and I must say that it is the best filter to have. It helps to filter out allergens. Everyone in my family suffers with allergies and are constantly sneezing, having a runny nose and burning eyes. Since I changed filters, we do not suffer as much as we used to and life is better.
The 1st set you sent us was really great almost eliminated dust in the house, the next set M11 not so good. Now we are trying M13s to see how they work.