Product review (2 stars): This Is NOT 41F
Apparently Broan has 2 filters that has exact same size: B29 for ducted and 41F for non-ducted. They are in the same size, just different thickness and different level of filtering. For obvious reasons, I'm guessing buyers would be looking for 41F for non-ducted, since the item description says so.

I've read a lot of speculations as to what the filter they had received, which was thinner and more loose. I don't know if it's the case of "knock-off" or not, but at any rate, I was told it would be 41F with 1/2 inch thickness. However, one that I received had the thickness of 2/3 of its description. As you can see in the picture, (from the product description), it should have thick cloth-like blue material at the other end as well, so that it could filter as many as possible. One that I received was definitely not meant to be used for non-ducted.

-- update 10/20/15

I returned what I received, and ordered through Amazon this time. And I have to say, it was 3 dollars well spent. It is generic; it is not a filter from Broan, but it fits Broan range hood, and the paper slip (as a manual) does mention Broan non-ducted range hood. That being said, now I find the returned filter highly suspect. That had nothing but a plastic package around it, and it was clearly meant to be used for ducted-model. I would advise you to check, if you have bought one of these, the density of the filter. If it is missing thick cloth-like filter at the end, I doubt it's meant to be used for non-ducted range hood. Besides, the item you had received does NOT have blue cloth-like filter, then you may request return/replacement, because that is clearly not what the description photo is showing.

Another thing I noticed from the proper filter was that it is meant to be used up to 12 months, while Broan customer support FAQ says up to 6 months. I don't know what caused that difference, but as always, the sign is the discoloration in filters, so check one in awhile (like every other month) to see if it worn down.

All in all, be careful not to go for the cheapest. That's all I can say.