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

Here is Why You Need An Adapter

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

Gabon

In Gabon, outlets of type C are in use.

Type C

Cambodia

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

Type A

Type C

Type G