Originally Posted by SpeedpeteDK

I think the one with a picture is the "normal" dB killer - that goes in the back end of the can. The other ones were not included in the package - but MTC sent them immediately after I said they were a bit too loud.
It took the high pitched smack sound off the pipes - will try to upload some sound files later on.
From MTC:
"They are classed as road legal however your bike is very loud once having any after market cans fitted. If you send me your address we can send you a couple of gauzes out that you slip in to the inlet end of your cans which will take a bit more of the noise away from them."