Restored Apple iMac 21.5" FHD All-In-One Computer, Intel Core i5-2400S, 4GB RAM, 500GB HD, Mac OS X 10.6, Silver, MC309LL/A (Refurbished) - Walmart.com
A-Tech 4GB RAM for Apple MacBook Pro (Early/Late 2011), iMac (Mid 2010, Mid 2011, Late 2011), Mac Mini (Mid 2011) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Module at Amazon.com
Apple iMac 5K Retina 27" Desktop - 4.2GHz Quad-Core i7 - 16GB RAM - 2. – The Refurbished Apple Store
4GB Memory for MacBook, MacBook Pro, iMac and Mac mini