Two Chinese characters - Ban Liang ("Half an ounce"), outer rim / Blank, no rims. 31mm, 4.72 grams. Hartill -; Gratzer/Fishman #A13.12. 

Very rare with the outer rim on obverse, rared "very rare" in Gratzer/Fishman.

Empress Lü, born Lü Zhi (241180 BC), was a brutal and fascinating figure of the early Han period. She was the empress-consort of Emperor Gaozu, the founder and first ruler of the Han Dynasty, becoming the first woman named Empress of China (as Empress Gao of Han). Empress Lü forbade private casting of coins in 186 BC, and ordered the government to cast the new heavy coins. The new Ban Liangs were cast to the heavy 8-zhu standard, cast to a theoretical standard of 6.7 grams. Despite the prescribed 8-zhu standard, the coins were either carelessly cast or were suffering from inflationary pressures, so many lighter coins, some weighing under 3 grams, are known (these lightest coins are often confused with the Qin State Ban Liangs).

This coin is unconditionally guaranteed to be authentic.