Q: Model year of my Laptop Pro so I may buy larger memory cards (want to put in a total 16 ...now has only 4)

I have learned (via entering my serial number into an Apple support site) my MacBook Pro is a 15" that is "early 2011" vintage.....so i guess that's all need to contact a board supplier and purchase the correct one.  found some boards listed on Amazon (2 X 8 GB) for about $65 to $75 including some sort of kit....hey, I don't like changing burned out light bulbs so this so should be a real test for me . ..

Thank you for the advice about not buying from Amazon or an electronics store......I checked on the crucial website and found a 16GB Kit for $69.99 .....looks as this may be what I am seeking. Next is the task that causes me to cringe ......installation .......VERY SCARY .....perhaps I need to visit a local 'repair' shop to seek their installing it for me. It may be 'easy-peasy' in their estimation but that's not the case for me.   Thanks again for your assistance. MUCHAS GRACIAS.