Dual Direction < Input 110/120V to Output 220/240V> Or <220/240V to 110/120V

You need to check the switchs' place at the bottom of the adapter(Black Swith ,Back ) That is:Switch to AC117V,input voltage must be AC110/120V,voltage converter (output) AC220/240 Switch to AC230V,input voltage must be AC220/240V,And change the voltage into (output) AC110/120V. Attention:it will be broken with wrong operation,and we will not responsible for the wrong operation.