Lenovo ThinkPad X61 Type 7767-01U 12.1" Tablet Laptop
2GB RAM Memory for Lenovo ThinkPad X Series X61s ( Type 7666 ) Black Diamond Memory Module DDR2 SO-DIMM 200pin PC2-5300 667MHz Upgrade - Newegg.com
2GB Memory RAM Upgrade for the Lenovo Thinkpad R61 Series, T60 Series, T61 Series, X60 Series and X61 Series Laptops (DDR2-667, PC2-5300, SODIMM) at Amazon.com