Two Chinese characters Ban Liang ("Half an ounce"), outer rim and inner rim / Flat, no rims. 24.5mm, 2.93 grams. Gratzer/Fishman "The Early Round Coins of China" #13.65 var (without the inner rim); Hartill #-. SKU T1916-50021
Very rare with the outer rim and inner rim - this variety seems to be unpublished and is not in Gratzer/Fishman. Rare with Shanzi Liang.
A Chinese ounce (liang) weighs about 16 grams. The earliest "Ban Liangs" weighed half that much - 8 grams, but the later pieces, like this one, weighed much less. These late Ban Liangs were cast during the reign of Emperor Wudi (140-87 BC), the date of the casting is ca.136-118 BC and they come from the last issue of Western Han dynasty Ban Liangs.
This coin is unconditionally guaranteed to be authentic