I'm always looking for a big exhaust to run on a big engine. Something that will quiet it down enough to ride in the hood when I'm testing a new engine, but big enough to let it breath. So I looked around for a muffler that would fit the cheap Chinese header pipe. I chose this one. (It's available cheaper straight from china.) https://www.ebay.com/itm/28mm-Black...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649 I was pretty impressed with it right out of the box. It's made of heavy gauge aluminum? and it's solid...no rattles or shakes. Mounted it on my 113cc 93 CT70 and it was loud, as expected. But it had a nice "tone", and if I put 1 finger behind the tailpipe it quieted it it noticably. So then I drilled out the rivets on the exit end and opened it up. Considered ordering a "DB killer" but didn't want to wait. Considered making some elaborate silencer gadgets, but decided to start with one of the easiest ideas. So here it is. It's loose inside so I can slide it end to end to find the best sound. Then I'll probably need to attach it somehow. I'll post again after I try it out.