For a couple of reasons I no longer use Amazon for memory so I tried to use Mr Memory. I looked up memory using my computer make and model and the memory that was suggested was correct, which meant I didn't have to take the memory out of my computer to look what I needed. For those who are not used to installing memory, there was even an email with clear instructions. My order arrived very quickly and adequately packaged. Unlike other companies, the modules came with clear suggestions and warnings of what not to do. I installed the new memory in slot 0 and 1 and my old memory in slot 3 and 4 and it all works perfectly. I now have 22gb ram in my old computer instead of 6. Great service and I will definitely use again.