Lenovo T420 Intel Core i3-2310M CPU @ 2.10GHz, 4GB RAM, 250GB HDD with Microsoft Windows 10 Professional and Microsoft Office 2010 Home & Business.
Lenovo T420 Memory Slots | Peatix
16GB (2X8GB) Memory Ram Compatible with Lenovo Thinkpad T420 4177, 4178, 4180, 4236 Series by CMS A13 at Amazon.com
16GB KIT (2 x 8GB) 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