Watch List notes:

ISLAMIC COINS, ABBASID REVOLUTIONARY, Anonymous, Silver Dirham, Sijistan 132h, obv central legend within square tablet, 2.84g (not listed by Klat). Struck on full broad flan, extremely fine and exceedingly rare, an unrecorded type for mint.
see The New York Sale XXX, Baldwin's / Dimitri Markov Coins and Medals / M&M Numismatics Ltd, January 2013 for an example of this coin which was sold in very fine condition from different dies

Estimate: £12,000-15,000