Most Savinellis (especially the 207 model) use the balsa filters. Possibly, the previous owner of your pipe took out the filter/adapter. Try getting some 6mm balsa filters for your pipe (or even cheaper is to use a pipe cleaner and snip off a 6mm length).
Keep in mind that if a pipe designed to hold a filter is used without the filter in place, the draw will be too loose and this could result in a hot, wet smoke. Using the adapter tube reduces turbulence within the shank, and you'll be rewarded with a much more flavorful smoke.