A canister runs back into the fuse sort of like a tuned pipe, bot normally exits toward the front. I Pitts style muffler just diverts the exhaust behind the cylinder but does not run back into the plane. It's called a Pitts style because it looks like the one used a full scale Pitts bipe. Pros & Cons. the Pitts is simple,cheap and efficient but only slightly quieter than a stock muffler. A canister is quiet, and can increase the power of your engine. It can be heavier, is more complicated to install and cost more. If you go to the Aeroworks site and look at the pics or even download the manual for their 50CC size planes, there are pics of both setups. Most AW planes are pre built to handle a canister or a tuned pipe. On the Extra 300 I have the lower portions of the fuse are pre cut and then the cover is put on over the exit point. So if a can or tuned pipe is used, it's only a matter of burning out the covering over the needed exit and cooling holes.

David