The generic 3rd party wall charger I have says 5V, 1A output. The little white cube that came along with my new iPhone SE says 5V, 1A output (gosh knows why they printed this in light gray microfont on the prong side of the cube). I assume that this is all that's needed for compatibility, and that there isn't anything sophisticated going on like communication with the charging device and modulation/pulsing of the charging current/voltage?
P.S. I found similar threads with either no answer or which was asked in the context of a specific device.