How to upgrade the RAM on your 13-inch MacBook Pro
A-Tech 8GB RAM for Apple MacBook Pro (Mid 2012), iMac (Late 2012, Early/Late 2013, Late 2014, Mid 2015), Mac Mini (Late 2012) | DDR3 1600MHz SODIMM PC3-12800 204-Pin SO-DIMM Memory Upgrade at Amazon.com
Apple MacBook Pro Mid 2012 - 13-inch 2.5GHz Core i5 Laptop Memory/RAM & SSD Upgrades | Kingston