CMS 8GB (2X4GB) DDR3 10600 1333MHZ Non ECC SODIMM Memory Ram Upgrade Compatible with Lenovo® Thinkpad X200 2024, 7454, 7455, 7457 - A29 at Amazon.com
X201, I think from about 2010 or 2011. It's a little slow, but with the ssd, 8gb ram (instead of 4) and running Linux Mint, it sure isn't bad for a 10+