I‘m unsure about the authenticity, based on the photos, but it is a known pattern from WW2. The hallmark is also known.
Normally, there would be a symbol on the face denoting the service the owner belonged to, e.g., Luftwaffe eagle or SS runes. Search the forum and you'll find several good, authentic examples. In the link below are some nice Norge Luftwaffe rings posted last year by John Z:
https://forum.germandaggers.com/ubb...=37069&Words=norge&Search=true#Post35078A word of caution though: whenever someone says that a ring was dug out of the ground, be suspicious that it's a fake or a copy. As others here will agree, being ground-dug, even if it actually was
"found" in the ground, is no any kind of provenance. And if a seller claims that he dug the ring himself, I don't believe it unless it was dug up a few decades ago and there is proof of this.