Name: Kontrabasharpa: A type of Nyckelharpa (Wiki)
Also known as:  Contra Drone Nyckelharpa
Family: Bowed String 
Wikidata item: Q58544416
Invented in: The 18th Century(1700s)
External links: http://nyckelharpsverkstan.se/kontrabas/
                        http://www.nyckelharpa.org/about/what-is-a-nyckelharpa/nyckelharpa-history/

Disambiguation: One row of keys but had two tangents on many of the keys 
Description: Has two melody strings on the opposite side of the bridge, between them is a drone string and about a dozen resonance strings.

Archived request from the wiki:

Kontrabasharpa

• Family: String?
• Description: Traditional Swedish instrument, similar to the nyckelharpa. More info.
• Appears on:
  1. Linnaeus Väsen played by Olov Johansson, credited as other string instruments