AIRx Filters Allergy MERV 11 AC Furnace Pleated Air Filter Replacement Box of 6, 18x20x1 Air Filter / 18x20x1 furnace filter Made in the USA

UPDATE: FYI! Watch your price on these... When I originally bought them in January 2017, they were $37.92 plus tax for a box of 6, but when I went to re-order them in August 2018, the price was jacked up to $50 and change before tax. Sooo... This year, I purchased "Aerostar Pleated Air Filter, MERV 13, 16x25x1, Pack of 6, Made in the USA" @ $37.99 instead, which--as you can see by the description--is an upgraded filter for the same price as I paid for these last year (MERV 13 vs. MERV 11).Before I purchased these, I did a lot of research as to what the different rating systems mean (MERV vs. MPR vs. DPR), who developed them, and how they compare to each other. Google it if you're curious. Very helpful. Armed with this knowledge, I purchased these filters and I'm happy with them. A few notes about the concerns of some of the other reviewers now that I've purchased these myself...1) "No markings on the filter--is this what I paid for?" - The MERV rating is very easy to miss, but it is there, so I've included a picture. (It's on the filter material, not on the frame.) Also, the brand and size can be found on the outside of the shipping box, which also doubles as a storage box for the filters, and features a label on the side where you can record the dates you've changed your filters. I've included pictures of all this, as well.My assumption about the lack of fancy packaging, color print, and copious labeling is that this is part of the reason these filters are offered at such an affordable price. I'll take it, especially since these are made in the USA. (Nobody sees the filter once it goes inside the unit, so I don't really care about the packaging. I just care that it does the job.)2) "I would've liked more folds." - The filters I received have a comparable number of folds to my old, name-brand filters. While I was looking at this, I noticed that the frame of these filters is actually sturdier than my name-brand filters on the non-airflow side, so I've also included pictures of both sides of each filter for comparison.3) "Annoying whistle." - I have not experienced this with the filters I received. I am happy with these filters, and will be purchasing again when needed.

Excellent filters - the cost to performance ratio on these is basically unheard of. No frills, no brand names, just top notch performance. Filters are put into our units and closed up to collect all the nasty stuff we don’t want blown around our house. As others have said, fancy packaging means nothing.One word of caution: you probably already know that these filters have a high MERV rating of 11. This is great to grab microparticles from the air and will undoubtedly help allergy sufferers. However, a higher MERV rating means more resistance for airflow. Many furnace systems are not capable of generating the air flow required to maintain proper operating efficiency with this resistance.To illustrate, my furnace runs wonderfully with a new filter. The issue is that it begins “short cycling” after approximately 3-4 weeks of these filters being in place. I realize many change out filters this often (as do I), but if airflow is restricted enough to cause short cycling when the time to change the filter out, damage to the furnace is already being done. Clearly this is no fault of the filters, it’s simply a symptom of a blower that’s not up to the task on my unit. The solution, as much as my allergies hate me for it, is to buy filters with a lower MERV rating. It is what it is. Just a word of caution to check your furnace’s specs to make sure it can handle these filters, and if your unit is aging, perhaps consider a filter with a lower MERV rating.

Great filters. Be prepared to swap these out more frequently than the lesser quality filters. Given these filters have a higher than 'normal' MERV rating, they will trap more particles, which inevitably means they'll need to be replaced more often than the lower MERV rated filters.

Works just like the expensive ones you get at big home improvement stores but at about half the price.If you're new to picking out filters, they come in a bevy of "efficiency" ratings (e.g. how small the particles and how well removed). However there's a trade off for a higher efficiency filter.Look at it this way: The perfect filter (allowing zero particles of the smallest size imaginable) would be a solid piece of cardboard, but that's not so good at letting air through, whereas the filter with the least resistance to air flow would be "nothing" but that's not good at removing particles.So the more efficient the filter, the more resistance to air flow, which translates into more backpressure on the supply of air, and less air flow into your house. So pick wisely (as in Indiana Jones).

I found an orange sticker on the box that lists these as MERV 1 and the printing of MERV 11 on the actual filters don’t align, match the same ink and was obviously added afterwards.Prior to posting this I reached out to AirX and they have yet to respond.This was an Amazon Featured product.

This product comes in bulk box not individually wrapped. Unlike the pics here it's actually an unbranded product. The filter is grayish in colour unlike other types which are white in colour. White is preferable as you can see that the filter is working as turns grey with use. The product quality and construction is good no issues there.

As good as other leading brands for less! Appreciate that the didn't come individually wrapped in plastic.

We have additional air filters around the house in addition to replacing the furnace filter regularly. Our air filters detected more air pollution/dust etc in the house when we used these filters, even when changed more regularly. I ended up throwing out half of the filters. I would not recommend this product, especially if you have asthma.

I bought this because this brand offers multiple size options, and I can get right one for my house. The price is also not expensive if comparing to other brands in store.