I picked up a bunch of them. They aren't made out of foam, they use a heavy gauze-like material. At that price, I'm not sure if I'll just replace them when it's time, instead of bothering to clean them.
Since they aren't foam, I don't believe they will have the filtration problem that K&N has. I haven't been able to visually observe anywhere where dirt could enter. The ones I have also fit well.