Tier1 21x27x5 Merv 11 Replacement for Trane FLR06070 BAYFTR21M Air Filter 2 Pack

perfect fit

I purchased these for replacement - but I have not had to change my last filter yet. They appear to be the correct size and good construction

This replacement filter fits the space correctly and appears to be an efficient filterl;

It's been a week since I ordered this, and it still hasn't been shipped. (Truth be told, delivery was only promised after two weeks.) Arrived finally 5/5/2017.Anyway, I checked into what 'Merv' stood for - turns out the higher the number the more effective the filter in removing progressively smaller and smaller particles from the air. But, that doesn't mean a higher removal rate is better - too much filtering effectiveness reduces the rate of airflow, and also reduces the unit's air conditioning effectiveness.Which one should you choose? Don't know - probably should ask the manufacturer.

Now that we went to Merv 11 the amount of dust in the air has dropped and it is noticeable when dusting furniture

The air conditioning tech suggested we buy at Amazon due to price. The filter is the size required. All works.

I got these to replace the pleated filters that have to be carefully arranged in the plastic housing. Placing it was so much easier. I did have to remove the pre-filter first as it was hanging up on that. I slid this filter in, then the pre-filter, eventually sliding this one out a bit and then both in together. It is a tight fit, but that is good for filtration.

Shipped undamaged, fit as expected