The Triumph one has some rubber bonded on that *very slightly* reduces chain noise. They have to do this and other seemingly useless rubber attachments such as the snorkles in the airbox to get the total vehicle sound level down enough that it won't disturb the cellphone idiots as they run over us.
If you have made absolutely no other mods to your bike AND have very sensitive hearing, you MIGHT notice the difference in the sound level.
