8GB 2X4GB Memory RAM for Dell Latitude E6400 XFR 200pin 800MHz PC2-6400 DDR2 SO-DIMM Black Diamond Memory Module Upgrade System Specific Memory - Newegg.com
CMS 4GB (2X2GB) DDR2 6400 800MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Dell® Latitude E6400, E6400 Atg - A39 at Amazon.com
2GB Memory Upgrade for Dell Latitude E6400 ATG DDR2 PC2-6400 800MHz 200 pin SODIMM RAM (PARTS-QUICK Brand) at Amazon.com
8GB 2x4GB PC2-6400 DDR2-800 Memory for Dell Latitude E6400 ATC , E6500 Upgrade | eBay