Volga and Karelian Finns

[Komi]

I am curious to learn about any foreign volunteer units which included Volga or Karelian Finns, and specifically what their service was like. For example, I have read that the Idel-Ural Legion included people like Mari and Mordvins, and I have seen a photo of at least one member of this unit who was described as a Karelian Finn. But I have no idea about things such as whether they served in their own sub-units or just mixed together with Tatars and other people, or in what theatres of the war the Germans sent their Volga and Karelian Finn volunteers to fight (for example, if any of them remained on the eastern front or were mostly transferred to western europe).