A-Tech 4GB Module for Lenovo ThinkPad T420 Laptop & Notebook Compatible DDR3/DDR3L PC3-12800 1600Mhz Memory Ram (ATMS350677B12034X1) at Amazon.com
4GB Upgrade for a Lenovo ThinkPad T420 System (DDR3 PC3-12800, Non-ECC, ) at Amazon.com
CMS 8GB (1X8GB) DDR3 10600 1333MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Lenovo® Thinkpad T420 4177, 4178, 4180, 4236 Series - A14 at Amazon.com
Lenovo T420 Laptop RAM + Hard Drive Location for UPGRADE or REPLACEMENT - YouTube
Help, what should I price my T420 at? Very good condition, i5 2540M, 8gb ram, Quadro NVS 4200M, new 256gb ssd, 1600x900 display, Windows 10. : r/thinkpad
How to Replace or Upgrade RAM Lenovo T420 - YouTube
OFFTEK 4GB Replacement Memory RAM Upgrade for IBM-Lenovo ThinkPad T420 (DDR3-12800) Laptop Memory at Amazon.com
Lenovo ThinkPad T420 i5 2.5GHz 8GB RAM 120GB Solid State Hard Drive 14" HD LCD Windows 10 Grade A Used - Walmart.com