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

Here is Why You Need An Adapter

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

Cambodia

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

Type A

Type C

Type G

Niger

In Niger, outlets of type C, D, E and F are in use.

Type C

Type D

Type E

Type F