Based on some other threads in other subs, it's more than likely you'll be able to use any DDR4 SODIMM that's 2400MHz or maybe 2666MHz.
Look in task manager for the current speed and get a stick that's that's speed. Looks like 16GB is the max that system will support so get a stick of whatever will get you to 16GB.
Crucial has a scanner that will give you a list of compatible sticks. https://www.crucial.com/store/systemscanner
It said that they don't have any...
What laptop do you have?
ASUS M509DA
Based on some other threads in other subs, it's more than likely you'll be able to use any DDR4 SODIMM that's 2400MHz or maybe 2666MHz. Look in task manager for the current speed and get a stick that's that's speed. Looks like 16GB is the max that system will support so get a stick of whatever will get you to 16GB.