I bought this coin without a catalog #, but identified as a fals of Mansur I from Bukhara dated 352-357. It is just about exactly 21mm and 1.50g.
Based on this, I used Stephen Album's Checklist of Islamic Coins (freely available as a .pdf released by the author!) and determined that this description best fits A#1471.1, described as being "Nearly all with diameter 21-22mm", struck in Bukhara in 352-357.
However, our page for A#1471 describes the coin as nearly 26mm, 4g, and most problematically, the image does not match my coin; my coin has four lines of text on the obverse, the one pictured has three. Granted, Album mentions 1471.3, described as a broad flan issue 25-30mm, so maybe the page describes that coin. But what about the different text? Any advice welcome.