A-Tech 64GB (4x16GB) RAM for Dell PowerEdge T320, T420, T620 Tower Servers | DDR3 1600MHz ECC-RDIMM PC3-12800 2Rx4 1.5V 240-Pin ECC Registered DIMM Server Memory Upgrade Kit at Amazon.com
8GB Stick for IBM Lenovo ThinkPad T Series T420 T420i T420s T520 T520i. 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 T420 4177, 4178, 4180, 4236 Series - A13 at Amazon.com
THINKPAD T420 RAM UPGRADE! (16GB) - YouTube
A-Tech 8GB RAM for Lenovo THINKPAD T420 4177 | DDR3 1333MHz SODIMM PC3-10600 204-Pin Non-ECC Memory Upgrade Module at Amazon.com