Counterpart

аналог

analog

(one which has corresponding functions or characteristics)

дво́йник

dvójnik

(either of two parts that fit together, or complement one another)

дво́йник

dvójnik

(something that resembles something else)

дублика́т

dublikát

(law: duplicate of a legal document)

еш

eš

(either of two parts that fit together, or complement one another)

ко́пие

kópie

(law: duplicate of a legal document)