Woodpecker makes a cute Expansion Chamber Exhaust a little smaller than the original YuanDong Big Boy version.
Measures 11 inches from flange to tip. Nothing inside so she's a loud puppy.
Welds are Mig welded; not by acetylene torch so they look a little better than YD's.
Will it fit all China 2 stroke bicycle engines? YES. Will it fit all bikes? NO.
Don't have any pictures with this muffler on a motorized bike so check around before you by. Buy one and tell me if it works OK and gives any mid range noticeable power increase. Send me a picture if it works OK or return for refund if don't work. We don't want to sell junk but who knows this might be>?