Lenovo Thinkpad X220 - How to upgrade RAM and the hard drive - YouTube
42912XU-RFB, Lenovo 12.5" HD, Intel i5-2540M (2.60 GHz, 3Mb L3), 4GB RAM, 320GB HDD, Intel HD 3000, VGA, DisplayPort, LAN, Wi-Fi, Windows 7 Professional (64) | EET
16GB KIT (2 x 8GB) for IBM Lenovo ThinkPad X Series X121e X220 Tablet X220i Tablet. SO-DIMM DDR3 Non-ECC PC3-10600 1333MHz RAM Memory. Genuine A-Tech Brand. at Amazon.com
CMS 16GB (2X8GB) DDR3 10600 1333MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Lenovo® Thinkpad X220 4287, 4290, 4291 Ddr3-1333 - A13 at Amazon.com
Lenovo ThinkPad X220 RAM Memory Cover 04W1416
Lenovo ThinkPad X220-Core i5 2nd Gen -12.5 inch HD screen-4GB RAM-500GB HD-windows10 - Refurbix