iMac (21.5-inch, Late 2013) - Technical Specifications
A-Tech 32GB Kit (4x8GB) RAM for Apple iMac (Late 2012, Late 2013, Late 2014, Mid 2015) | DDR3 1600MHz SODIMM PC3-12800 204-Pin SO-DIMM Max Memory Upgrade at Amazon.com
Apple iMac 21.5" A1418 Intel Core i5-4640 / 8GB Ram Logic Board P/N 820-4668-A for sale online | eBay