Thank you for your message. I have looked in to this further for you. The good thing is the original memory you have installed is a Micron memory module. Crucial are part of Micron so I was able to look up the part details of your existing memory.
This is the same speed and type as the memory you have installed. It will work perfectly together and take your system up to 16GB in total. We also have a great guides and support section on our website here: http://www.crucial.com/usa/en/support
If you do have any other questions, please don’t hesitate to ask.