the tank has a blurdy great "hump" in it I guess to locate the tank pad
 Its about the size of a goodly marble (from my schuuldays, you see), and I had to replace it wiff an original from Ducati as thinner versions didnt fit
 Good luck if you find a thinner one, but I must admit when I replaced mine, the ole crown jwels came to mind first
 rgds
 mort

