Simple really, I use it because it works. There's no differance in the materials or the construction of this small filter compared to one of their world class larger filters. It's original design is for a dry sump oil system, it's a breather really. Mainly for your off-road type's (Baja & stuff). I get mine directly from K&N, alot cheeper than the RC guys sell them for and you can get them sized to fit any carb. If I wasn't running this I would probably be using a Motor Saver, I don't care for the typical foam filters. They lack in performance & looks (2 for $5, come on).