You are buying ONE coin from the pile of coins. Most if not all will be Faustina II. Some if not all of the reverses will be described below. The sizes of the coins range from 18-22mm

Another dealer bought a large lot of coins of Faustina II and these appear to be from that same hoard. His notes are in italics

This coin is part of a large hoard consisting of 673 pieces Faustina II. plus 4 coins of Crispina. It hit the market abt. 15 - 20 years ago without any information on site or circumstances how it was found. The coins were not cleaned but show a uniformly shiny patina. Many are extremely worn. Still, all coins are attributed with special consideration of die varieties. Nobody knows why this hoard consists of Faustina II. coins only (the 4 Crispina coins might have been taken erroneously in because in a worn state, they like very similar to Faustina coins.)

Examples of Obverse and reverse types:

Obverse: FAUSTEINA SEBASTH, Head of Faustina II  right.
Reverse: OULPIAS PAUTALIAS, Fortuna standing left, holding rudder and cornucopiae.  

Obverse:  FAUSTEINA SEBASTH, Head of Faustina II right.
Reverse: OULPIAS PAUTALIAS, Pallas Nikephoros, seated left, resting on spear; at her side, shield.