That's a SLIMLINE muffler. It is identical to the Slimline on my Brison 2.4. I believe the engine in the pic. is a Brison also. If it is the "quiet" Slimlne the exhaust pipes go all the way to the other side of the muffler ( detectable by 2 little bumps ) and the pipes inside the muffler are drilled full of holes. This arrangement is supposed to be a baffle of sorts. It does nothing for the noise but it does choke the exhaust off and lower power output.