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
A-Tech 8GB Memory RAM for Lenovo Thinkpad T520 4240 - DDR3 1600MHz PC3-12800 Non ECC SO-DIMM 2Rx8 1.5V - Single Laptop & Notebook at Amazon.com