Poka

Monitor says it supports adaptive-sync so it should give a good experience even if you don't hit 144 Hz, which will depend a lot on the game itself, the settings, and also the CPU.
 
BTW it is just Hz. "mhz" doesn't exist. "mHz" would really suck, and "MHz" would be insane.

Yes also the system read it as 16 GB ram now so i think i was succesfull on plugging it in correctly

i'll take the safer bet and get the same latency and frequency , as i'd really like to feel the improvements  
 Appreciate your help man , will for sure thumbs up thank you very much.

Yeah generally you should be fine with a stick that runs at the same latency and frequency, it doesn't necessarily have to be the same brand.
You could even go for different timings/speed but your RAM will run at the speed and timings of the slower/looser memory stick.

Perfect Thank you So Much ! Will order one tommorow

You could try, in theory, yes it would, but it might not.  
 
When it comes to RAM and the labeling of it, you get a very small amount of information you get the Speed, CAS, and a few main timings.  There are quite a few sub timings involved that also need to be stable. If the two brands happen to also be using the exact same dye, Samsung B Dye for example, will usually need different sub timings than a Hynix dye.  Putting them on Auto might work, you might get lucking and you find a combination of those timings that work.  But all it takes is one of those variables to be out of an acceptable range of one of your sticks of RAM and then you'll lose stability. 
 
What RAM does often gets overlooked, but it's essentially the time keeper for everything in your system, if it's not running smoothly, then the whole system doesn't function well.