Can this charger bought from the internet from china damage phone ?

I have usb voltage amp test device
the one you insert it into usb port

in my original phone charger it says in the usb voltage amp tester:
5.06 volt 0.42 Amp

I bought a cheap phone charger from china from the internet for about 2 dollars

in the phone charger I bought from china the usb voltage amp tester:
4.72 volt 0.37 Amp

could this low voltage for the Chinese charger damage the phone ?
and could this lower Amp damage the phone ?

What is the safe lower Amp the phone can use that will not damage it ?