You Do Need power plug adapter while traveling from Jordan to Eritrea.

Here is Why You Need An Adapter

The outlet and plug type used in Eritrea are C and L and in Jordan are C, D, F, G and J. This is how they look like.

Jordan

In Jordan, outlets of type C, D, F, G and J are in use.

Type C

Type D

Type F

Type G

Type J

Eritrea

In Eritrea, outlets of type C and L are in use.

Type C

Type L