A very nice piece with well-preserved details.
A variety with an eagle of the old type, appreciated by Bitkin with a high degree of rarity R1.
Obverse: eagle of the Empire of the 1844 pattern, between its legs and tail the initials ПА, in a corded border, in the outer border an inscription beginning with a rosette:
ЧИСТAГО СЕРЕБРА 4 ЗОЛОТНИКА 21 ДОЛЯ;
Reverse: in a laurel and oak wreath crowned inscription:
MOHETA/РУБЛЬ/1849/СПБ;