Helvetii AE Cast Potin unit, Zürcher type

Central Europe, Helvetii. AE Cast Potin unit (17-18 mm, 4.17 g), early 1st century BC. Zürcher Type.
Obv. Thunderbolt.
Rev. Mountain goat standing left, his head turned back to right.
SLM 905 ff.

Rare. Green patina. Insignificant edge-ship, otherwise, good very fine