Don’t require power plug adapter while traveling from Guinea-Bissau to Poland.

Here's why you do not need an adapter

The outlet and plug type used in Poland are C and E and in Guinea-Bissau is C and they are compatible with each other.

Guinea-Bissau

In Guinea-Bissau, outlets of type C are in use.

Type C

Poland

In Poland, outlets of type C and E are in use.

Type C

Type E