Hi ....
Based on your Macbook model, a simple search says....
http://www.crucial.com/usa/en/apple-memo...
http://www.crucial.com/usa/en/compatible...
http://www.kingston.com/en/memory/search...
You need two 8GB DDR3L RAM = 16GB
Based on my experiences, either go for crucial or kingston which is specially designed for apple macbook.
there are cases using 3rd party which causes issues.
it would be good, if the shop is okay to do a in place upgrade and test on spot.
http://www.everymac.com/systems/apple/ma...
*Apple officially supports a maximum of 8 GB of RAM, but third-parties have determined that this model actually is capable of using up to 16 GB of RAM with two 8 GB memory modules.
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