Matching timings is nice, not necessary.

Yes. Any DDR4 8GB stick will work, but you might lose a little performance or get rare crashes if you mix wildly different speeds/timings.

Your laptop is dual-channel, so ideally the two sticks match. But if you can’t find the exact same model, grab another 8GB DDR4-3200 (that’s your Predator’s native speed) and it’ll be fine—it’ll just run both sticks at the slower one’s specs. The system will downclock automatically.

If you want zero headache, match the voltage (1.2V standard for DDR4) and get the same CAS latency. But honestly? I’d just buy a single 8GB stick with the same or higher speed rating. Worst case you’ll never notice the difference in games or work.

One thing: make sure it’s a laptop SODIMM, not desktop DIMM. Easy mistake.

Don’t overthink this—just don’t buy the absolute cheapest no-name RAM off eBay.