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
Mid 2007 iMac Upgrade. MAX Specs,SSD,And Catalina! - YouTube
4GB kit (2GBx2) Upgrade for a Apple iMac (Mid 2007) System | eBay