In the USA the power is 110V 60Hz
In Europe it's 230V 50Hz
What counts is the voltage of the power supply to your house - any (all) appliances should match.
Check out any working appliance - a kettle say - and you'll know the voltage.
Go to a store in your country and the shower you buy will be the right voltage - in Europe they would not sell you an American 110V shower similarly in America they would not stock European units.
A most odd question..., January 2016