You Do Need power plug adapter while traveling from Puerto Rico to Equatorial Guinea.

Here is Why You Need An Adapter

The outlet and plug type used in Equatorial Guinea are C and E and in Puerto Rico are A and B. This is how they look like.

Puerto Rico

In Puerto Rico, outlets of type A and B are in use.

Type A

Type B

Equatorial Guinea

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

Type C

Type E