MacMemory Net 6GB DDR2-800 PC2-6400 DDR2 800Mhz SO-DIMM Kit for Apple iMac Model 8,1 (4GB + 2GB) 6GB DDR2-800MHz SO-DIMM (4GB + 2GB) for iMac 8,1 Late 2008 In order to make enough room for other applications running on OS X Yosemite, we recommend upgrading your RAM to a 6GB tested maximum Optimized and rigorously tested for Macs All Ramjet products are sold exclusively by the Ramjet Store