Based on his studies of Hunnu and later Tyurkic tamga-stamps A.Y. Shifner (1817-1879) comes to the same conclusion. He maintains that these tamgas display all currently known runic symbols, both western (Scandinavian and European) and eastern (Siberian). These stamps are the only surviving examples of Hunnu runes because the leather and bark used for ordinary writing have disintegrated long ago.
Dmitry Ermakov in Bo & Bön p. 710