Adamanta 16GB (2x8GB) Memory Upgrade Compatible for Apple Mid 2010, Early 2011, Mid 2011, Late 2011 iMac DDR3 1333Mhz PC3-10600 SODIMM 2Rx8 CL9 1.5v Module RAM at Amazon.com
iMac RAM Models 11.3 (i5 and i7 only) to 12.2 (8GBx4) | MacMemory.com
Install memory in an iMac - Apple Support
Timetec Hynix IC 8GB Compatible for Apple DDR3 PC3-8500 1067MHz /1066MHz SODIMM Memory Upgrade for MacBook 13 Mid 2010, MacBook Pro 13 Mid 2010, iMac 27Late 2009, Mac Mini Mid 2010 (8GB) - Walmart.com
Apple iMac A1311 21.5" AiO Computer i3-540 (Mid-2010) -
Timetec Hynix IC 16GB KIT(2x8GB) Compatible for Apple DDR3 PC3-8500 1067MHz/1066MHz Upgrade for MacBook 13'' Mid 2010, MacBook Pro 13'' Mid 2010, iMac 27''Late 2009, Mac Mini Mid 2010(16GB KIT(2x8GB)) Laptop Memory -