Before you make the purchase, go to the vendor website to see if the memory is compatible with the version you are considering. Some laptops are very picky regarding the timing of the RAM they will recognize.
I would recommend you remove the RAM currently in the system and write down the memory settings/timings that are generally on a label on the SO-DIMM itself. Try to match, as closely as possible, the RAM the system expects to use.
These steps may keep you from a future RMA or return (I have experienced this firsthand before). Good luck!