The muffler towels are smaller. YesAsia also has measurements, you should check them out. I believe the mufflers are the same length as sport towels, but only half as wide, which make them good for wrapping around the neck or face. Sports towels are just.. regular towels.
Here's a picture of my Asia Tour 2008 Sports Towel.
In the SPOILER there are pics of it with CD's on it, so you can check for the size comparison.
