because the guy that created them said to buy them from him. lmao

muffin fans are pretty good for a cfl grow, but when you start getting into the larger hps lights they really dont work much. the muffins along with inductor/booster fans under a load really dont have the balls to move the air like the inlines do.you can search around and get a very reliable inline for about 100-200 depending on size you need. and another thing is when hooking up to a carbon filter and cooltube, youll have environment around a maximum and smell taken care of