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Lenovo ThinkPad T420/T420i - iFixit
Lenovo ThinkPad T420 14.0 Laptop, Intel Core I7-2620M up to 3.4Ghz, 8G DDR3, 240G SSD, DVDRW, DP, W10P64-Multi Languages Support (EN/ES/FR), 1 year warranty Used Grade A - Walmart.com
A-Tech 8GB RAM for Lenovo THINKPAD T420 4177 | DDR3 1333MHz SODIMM PC3-10600 204-Pin Non-ECC Memory Upgrade Module at Amazon.com