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

Here's why you do not need an adapter

The outlet and plug type used in Greece are C and F 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

Greece

In Greece, outlets of type C and F are in use.

Type C

Type F