The fram filters are the worst, you can not compare a K&N with fram.
K&N are synthetic filters they filter down much farther than a normal filter.
K&N filters are the same filter as a Mobil 1 filter but they welded a 1" nut on the end. Both synthetic.
There are two sizes and I have used them both, but I think the larger is better because of capacity, It has more filter paper in it.