This is a pair of Oberleutnant’s shoulder boards for one of two Prussian Bataillone. They would come from Jäger-Bataillon Nr 20 or Pionier-Bataillon Nr 10. In addition to the “10” that designates the unit, it sports an Oberleutnant’s single pip.
The shoulder boards’ reverses reveal red backing, and are of the slip-on rather than the sewn-in variety. [This was a bit unusual for such a junior officer. Normally, he would have used the sewn-in variety]. We know they were used on a tunic due to the depression where the buttons once held them down. They are in very fine condition.