A lot of differently branded oil filters must be made in the same factory with many of the exact same materials. While at AutoZone, I looked over the filters spec'ed for the '06 Camry Inline-4, and found that the Mobil 1 103 filter, the K&N filter, the AC Delco oil filter, and the STP filter all look * exactly * the same, except for the color of the filter cans. If they were all the same color, I couldn't tell one apart from the other--that's how similar they look: identical really. I guess there is one difference: the rubber-like gasket below the ring of holes is orange-colored in the Mobil 1 and the K&N filters and black-colored in the AC Delco and the STP. But that's it. Everything else looks identcial. All 4 filters even share the same "blue button" that can be seen down inside the long, hollow center hole. These 4 filters must share a whole lot of the same construction materials. I guess it's what you can't see from the outside that counts. I suppose the internal filtration media is quite different between these 4 filters since the filters are priced very differently: $13 for the Mobil 1, $16 for the K&N, $6.xx for the AC Delco, and $3.50 for the STP. The Fram is $4, but it looks way different from the other 4 filters and is taller. Oh, one other detail: the K&N filter has a 1-inch wrench thingie sculpted on top so you can unscrew the filter from the car using a regular 1-inch wrench, instead of a special filter wrench. Although these 4 filters are all spec'ed for the '06 Camry I4, they're all about 1/2-inch shorter in height than the OEM Toyota/Denso filter specified for the Camry (cost is $6.xx at the dealership for the Denso). A newbie could easily conclude that the Denso has a much larger filter capacity because of the Denso's taller height. The other 4 filters look like tiny things next to the Denso, even though all 4 filters and the Denso have the same diameter.