First, you would have to make sure your laptop has enough physical slots for more ram. If not, you would need to buy a 8GB stick of ram rather than a 4GB stick.
For ram, you would always want to try to get them to match. That would mean having the same brand, size, timings, and latency. This would appear to be the closest match for the ram you have (I simply googled the part number from your screenshot):
https://www.amazon.com/Kingston-4GB-1Rx8-PC3L-12800S-TSB16D3LS1KBG/dp/B00XLRVH2E
However, it is still not guaranteed to work perfectly with the preexisting ram you have in your laptop. You might have to run a program called Memtest to make sure you do no get any errors. Sometimes manufacturers might change out the chips they use on...