Horseman advancing right, holding a spear / Inscription in 4 lines "KNZ bVELIKIY IVAN PSK" ("Grand Duke Ivan PSK"). 16mmx11mm, 0.63 grams. Moscow mint.  Griszin #73; Russian Wire Coins #73.

This is a full kopeck (not a denga), weighing 0.63 grams. The coin was minted in Novgorod around 1540 when Ivan was still just a Grand Duke and not a Tsar.