What is the power input to the iPhone 7 and where is the spec page?
Generally, iPhones are 1A, iPads are 2A.
So long as the voltage is correct, the amperage doesn't really matter.


If you try to charge a 2A device with a 1A charger, it will charge more slowly.
If you charge a 1A device with a 2A charger, you won't see any difference to a 1A charger.


Amperage is "pulled" by the device, not "pushed" by the charger.