The specimen is preserved in 70% isopropyl alcohol (rubbing alcohol).
Vial is approximately 2.5in tall.
More about Vespa mandarinia:
Also known as the yak-killer hornet, Vespa mandarinia are found in Japan. These fantastic beasts create nests by digging tunnels, co-opting pre-existing tunnels dug by rodents, or occupying spaces near rotted tree roots. They feed primarily on larger insects, tree sap, and commonly steal honey from honey bee colonies! Also, their sting is excruciating and they are responsible for 30-40 human deaths a year in Japan!
https://bicbugs.com/product/vespa-mandarinia-queen-wasp-hornet-japan/