Sorry Andy,its not a missprint-67mm it is!
But thats the outlets on the 2005 spec tailbox and it is VERY loud ,John assures me its 104.9 decibels -honestly officer .
Not sure what will happen on the Bikecraft day ,i think i'll have to stick a couple of socks in it to quient it down (Guicci's of course!!!)
Butch