A-Tech for Apple 6GB Kit (1x2GB + 1x4GB) DDR2 667MHz PC2-5300 200-pin SODIMM for MacBook (Late 2007, Early 2008, Early 2009), MacBook Pro (Mid 2007, Early 2008), iMac (Mid 2007) - Memory RAM Upgrade at Amazon.com
Review: Apple's new 24-inch iMac (aluminum) | AppleInsider
Apple iMac 2007 A1224 MA877LL/A 20" C2D 2.4GHz 4GB RAM 320GB HD DVDRW El Capitan 885909150335 | eBay
A-Tech for Apple 4GB Kit 2X 2GB PC2-5300 667MHz Mac Mini iMac Late 2006 Late 2008 Mid 2007 A1208 MA589LL A1207 MA456LL A1200 MB138LL/A A1176 MB139LL/A Memory RAM at Amazon.com
6GB Memory for 2007-2008 MacBook Pro, MacBook, and iMac
Memory Upgrades for Apple iMac 2007 - Up to 6GB
4GB 2 X 2GB DDR2 Memory for iMac 7,1 Mid 2007 20" inch 24" inch Intel Core 2 Duo 2.4GHz PC2-5300 667MHz 200 pin SODIMM (PARTS-QUICK) at Amazon.com