How to Replace or Upgrade RAM Lenovo T420 - YouTube
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
MEMORIA 16 GB 2x 8 GB RAM per Lenovo ThinkPad T420 T420s T420i T430 T430s EUR 67,90 - PicClick IT