Date : The exact dating of Ban Liang coins is not well understood, but I believe this size and weight of this Ban Liang belongs to the coinage reform of 179 BC, as discussed on my reference guide to Chinese coins at : Ban Liang dating
Denomination : Ban Liang (meaning 1/2 ounce).
Reference : Schjoth - 93 variety.
Size : 23.2 x 24.6 mm. Weight : 2.45 gram.
Grade : VF with a dark green-brown patina, with some thicker brown encrustations.
Obverse : "BAN LIANG", meaning 1/2 ounce.
Reverse : blank.