Lenovo ThinkPad T400 14.1" Laptop C2D 4GB 250GB HDD Windows 10 Home
8GB Kit (4GBx2) Upgrade for a Lenovo ThinkPad T400 Series System (DDR3 PC3-12800, Non-ECC, ) at Amazon.com
8GB (4GBx2) Team High Performance Memory RAM Upgrade For Lenovo ThinkPad T400 Series T410 Series Laptop. The Memory Kit comes with Life Time Warranty. at Amazon.com
Lenovo Thinkpad T Series T400 RAM Repair Guide | Installation Video
2GB DDR3-1066 (PC3-8500) RAM Memory Upgrade for The IBM ThinkPad T400 Series T400 (7417P5U) (Genuine A-Tech Brand) at Amazon.com