Seal of a Hephthalite governor 5th-6th C. CE

"A seal bearing the legend ηβοδαλο ββγο, "Yabghu/governor of the Hephthal," shows the local, Bactrian form of their name, ēbodāl, which is commonly abbreviated to ηβ on their coins"

-taken from Wikipedia

Source:

https://data1.geo.univie.ac.at/projects/dasantlitzdesfremden/showcases/showcase10%3Flanguage=en.html

https://en.wikipedia.org/wiki/Hephthalites

https://en.wikipedia.org/wiki/File:Seal_of_a_Hephthalite_king_with_the_Bactrian_inscription_The_Lord_(Yabgu)_of_the_Hephthalites._End_5th_century_early_6th_century_CE.jpg