Here's why you need an adapter
The outlets and plugs used in Niger are C, D, E & F. Take a look at the pictures below to see what each plug and socket type looks like.
Voltage and frequency American Samoa vs Niger
All outlets in American Samoa provide a standard voltage of 120V with a frequency of 60Hz.Voltage: 120V Frequency: 60Hz
All outlets in Niger provide a standard voltage of 220V with a frequency of 50Hz.Voltage: 220V Frequency: 50Hz