Trial version. Type of portrait reminiscent of the ruble sample 1766 standard coinage, but with the head large in size.
In a circle the front and back of a rim with notches (on some coins may partially be absent, it is not a marriage).On the obverse
is a portrait of Catherine II in profile, face to the right. Under the portrait letters "СПБ"(Saint-Petersburg), the shoulder cut letters "Т I"(initials of Timothy Ivanovich Ivanov, the author of the portrait). In a circle the inscription - "Б•М•ЕКАТЕРИНА•II•IМП•IСАМОД•ВСЕРОС"(stands for "the grace of God Catherine II Empress and autocrat of all Russias").The reverse
depicts the coat of arms of the Russian Empire
of second half XVIII century: the double-headed eagle with the lifted wings, crowned by two Imperial crowns, above the same crown but larger. Right Talon the eagle holds a scepter, the left power. On the eagle's breast shield with the Moscow coat of arms: St. George on horseback slaying a serpentine dragon with wings. The shield surrounded by chain of Order of St. Andrew. Under the clutches of an eagle letters "Я I"(initials of mintmaster mint). At the top in a semicircle the year of issue "1766". At the bottom a semicircle of nominal - "МОНЕТА • РУБЛЬ"(letters converted basis inside).