This one has the "insulator symbol" inside a large C and has what looks like a backwards letter N inside, this is the Cyrillic letter И, equivalent for the letter I, The И is for Изоляторы (Insulators)

Manufacturer is apparently Slavyansk СЛАВЯНСК . (Ukraine). Date 1971. The embossed characters to the left are ШС 10 A which are the cyrillic equivalent of "Sh S 10 A"

The embossed symbol is the same as on this porcelain insulator [id=268746362]