Horseman advancing right, holding a spear, "A" below the horse (off-flan) / Inscription in five lines "KNZ bVELIKIY GAR VSEYA RUSY" ("Grand Duke ruler of all Russia"). 16mmx10mm, 0.68 grams. Pskov mint. Griszin #74; Russian Wire Coins #74.
This is a full kopeck (not a denga), weighing 0.65 grams. The coin was minted in Pskov around 1540 when Ivan was still just a Grand Duke and not a Tsar.