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

Here is Why You Need An Adapter

The outlet and plug type used in Cambodia are A, C and G and in Eritrea are C and L. This is how they look like.

Eritrea

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

Type C

Type L

Cambodia

In Cambodia, outlets of type A, C and G are in use.

Type A

Type C

Type G