USSR
0.58 - 0.7$
price on 20.02.2023
Unique serial number at centre right.
| Country: | USSR |
| Type: | Postal blocks |
| Series: | Nature preservation |
| Nominal: | 50 k |
| Year: | 1986 |
| Material: | coated |
| Size: | 61 x 91 mm |
| Perforation: | frame 11½ |
| Mintage: | 800,000 |