Apple iMac 21.5" - 8GB RAM - 250GB - macOS X - a1311 3.2 GHZ UPGRADED 603784376509 | eBay
4GB RAM - Memory (PC3-10600) for Apple MacBook Pro 15 inch A1286 13 inch A1278, 17 inch A1297, Mac mini Unibody A1347, iMac 21.5 inch A1311, 27 inch A1312 (Early 2010 -Late 2011)MacWave
NEMIX RAM 32GB (4x8GB Upgrade) DDR3-1333 PC3-10600 204-Pin SODIMM Memory for Apple MacBook Pro Early/Late 2011, iMac Mid 2010 27 inch 4-Core, iMac Mid 2011 21.5/27” , Mac Mini Mid 2011 at Amazon.com