The Museum of National Antiquities in Stockholm has eight Viking-Era keys with a uniform look, all from archeological digs in the Värnamo region of Jönköping County in southern central Sweden. Another four keys from the same region are preserved at the Jönköping County Museum. These twelve keys, along with one found in Halland County, two from Kalmar County, one from Skåne, and three from the island of Bornholm, form a uniform and thus far undocumented group. All have an S-shaped bit and are forged out of iron.
It is curious that no key of this type has been discovered in the large, well-documented digs in Helgö, Birka and its home island of Björkö, or in the province of Uppland. Nor are they found in other Scandinavian Viking-Era digs in Aarhus or Ribe in Denmark, or in Coppergate (Anglo-Scandinavian Ironwork) in the UK. No such keys are found in lock and key collections in the rest of Europe either.