My mower is a Craftsman 21" rotary push mower with a Briggs engine. Having a name brand gives some insurance the part will perform properly. And since I don't know the integrity of the off-brand air filters, I bought these Craftsman air filters. The filters themselves have 'Briggs & Stratton' and their P/N printed on it. With some searching, these were about the same price if not too much more than the off-brands I looked at. I already installed one along with a pre-filter from another purchase. The mower bogged down a bit, but a lot less than with the dirty filter it replaced (the grass was drier [dryer?] but somewhat taller on the 2nd mowing). Maybe some or all of the off-brands are adequate and some a bit cheaper in price. But in this case, for the small difference I'll stick with the name brand.
6.25 Briggs & Stratton Air Filter / Murray Push mower
The filter fit perfectly, I took all measurements prior to ordering. I then Cross referenced other part #
to verify fitment. I am sure its a probably Chinese product, unfortunately that's what lazy people and greed have caused in the USA .