8GB 2X 4GB Memory Compatible for Apple iMac Core i3 i5 i7 Mid 2010 DDR3 PC3-10600 204 pin 1333MHz SODIMM RAM (PARTS-QUICK Brand) at Amazon.com
A-Tech 32GB (4x8GB) RAM for Apple iMac (Mid 2010 27 inch 4-Core, Mid 2011 21.5/27 inch) | DDR3 1333MHz PC3-10600 204-Pin SODIMM Memory Upgrade Kit at Amazon.com
iMac RAM for Model 11.2 to 12.2 | DDR3-1066MHz | 4GBx2 | MacMemory.com
Timetec Timetec 8Gb Kit(2X4Gb) Compatible For Apple Ddr3 1067Mhz / 1066Mhz Pc3-8500 Cl7 For Mac Book, Mac Book Pro, Imac, Mac Mini (Late 2008, Early/ Mid/Late 2009, Mid 2010) Sodimm Memory Mac Ram
Is it worth it to upgrade RAM on Mid 2010 21.5 iMac? | MacRumors Forums
Apple iMac 3.0Ghz Core 2 Duo 21.5-Inch (Late-2009) *No HDD/RAM* – MSU Surplus Store
4GB PC3-10600 RAM for Apple iMac Mid 2010 - 21.5 Inch MC508LL/A Memory Upgrade Module
Apple iMac 21.5" Mid 2011 A1311 i5 2.5GHz 12 GB Ram 2TB HD Radeon HD DVD GRADE A – I.E.T. INDUSTRIAL ANTONIO PRIETO – SINCELEJO, SUCRE