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 PC3-12800 SODIMM 204-Pin Memory Upgrade at Amazon.com
Spent 2 months upgrading this 2012 MBP to absolute MAX spec : r/mac
Memory RAM Upgrade for Apple MacBook Pro 13-inch Mid 2012 4GB DDR3 SODIMM | eBay