You go to their web site, plug in your device information and it lists compatible RAM. I've used them many times with nary a problem.
I am looking to max out my laptop memory (8 Gigs). My issue is that I am from the school that all computer components are the same. Let me know of any product preferrence that you have and why. I've looked at Kingston and PNY but I can't decided which I want to go with.
System: Sony Vaio VCPEB290 X; Core i5 @2.53 GHz; Win 7 Ultimate 64 bit; 4 Gigs RAM