I actually just replaced mine and I got the 12" blades. I really cant see anything over that cause mine just misses touchin the seal (by just misses, I'm talkin within a 1/4"). Yeah nobody really carries them, but any main auto parts store should be able to get them with in a day or 2. Kind of a funny story about no one carrying them, I went in to pick up a set, and two older guys were dealin with me (musta been slow). One of them looked it up and had a weird look on his face, He said 12". The other old man looked puzzled and asked "What the hell do you have?", and insisted it was at least 13". I said a jeep wrangler and it should be 12", and he still couldnt believe it till I walked out with him and showed him. I thought it was pretty funny.