4GB [2x2GB] DDR2-667 (PC2-5300) RAM Memory Upgrade Kit for The Apple iMac 7,1 (20-inch, 2.0GHz, MA876LL/A) Intel Core 2 Duo (Genuine A-Tech Brand) at Amazon.com
Apple iMac 20" Desktop Computer PC Core 2 Duo 4GB 160GB Mac OS X Capitan (A1224)
Apple A1225 24-inch iMac 7.1 Core 2 Duo 2.4GHz 320GB HD 2GB RAM Mid-2007 MA878LL | RecycledGoods.com
Amazon.com: Apple iMac ME087LL/A 2GB RAM Core 2 Duo 2.0 GHz 160GB SSD (Renewed) : Electronics
Apple Mac 4GB Memory 2x 2GB 667MHz DDR2 PC2-5300 SODIMM RAM for MacBook Pro iMac | eBay
CMS 2GB (1X2GB) DDR2 6400 800MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Apple® iMac Core 2 Duo 2.8 24-Inch (Early 2008) - A40 at Amazon.com
iMac RAM upgrade: Here's an affordable way to improve multitasking - CNET