very irrelevant question about voltages and amp

[electrical_illiterate]

Hi, I have an old GPS system, which I think runs on 5V and 1.2A. I am thinking about buying a universal car charger to use with it because I no longer have the old charger. Even though I kinda have an idea of what volt and ampere means, I just want to be sure as not to damage the GPS:

1) If the machine requires 5V, the charger must supplies 5V exact right? The adapter cannot supply like 4.5V or 6V?

2) What's about the Ampere? As far as I know, if the charger supplies more Amp than what the GPS requires (like 2A charger for 1.2A GPS system), it is OK, but the charger cannot deliver less Amp than what the device needs?

Any clarification would be appreciated. Thanks!!!

 

[Resqueline]

You are perfectly right at both points!
In an emergency you could get away with 4.5 or 6V though but it's not good, risk of dropouts/glitches/errors or running hot.
Just remember to check that the polarity matches too.