Short explanation: So these are DDR3 SO-DIMMs which you can find out by size and where the notch is located or via googling what is written on them. Those are the two hard specifications you have to keep to make the replacement fit into your laptop. Without going too much into detail: If they fit, they should work in most cases.

Everything else is performance, so more GB is already better and always use 2 or 4 sticks if possible. Now it comes down to speed which is also written on. Might be that your laptop is limiting to the clock speed used which is 1600Mhz but if you find a faster one which is cheaper it will not hurt. Rather go lower with the CAS latency (you have 11-11-11) which might give a slight performance boost your laptop will be able to use.

TLDR: 2x 8GB DDR3 SO-DIMM 1600Mhz CL11 is what you have. The consumer market maximum amount is pretty much 2x8GB. DDR3 SO-DIMM is the mandatory physical specification. 1600Mhz CL11 is the speed you have. 1600Mhz CL9 or 1866Mhz CL 11 are possible but the latter might be limited to 1600Mhz CL11 in your system. https://www.gskill.com/product/2/159/1537259112/F3-1600C9S-8GRSL