Full Details from Amazon.com : http://www.amazon.com/gp/product/B0044V2QHG?tag=onigi-20
8GB 2 X 4GB DDR3 SODIMM 1066MHz PC3-8500 204 pin Lenovo ThinkPad X200 X200s X201 x201i X201s
Halogen Free ROHS
Speed PC3-8500 DDR3 1066MHz
Form Factor 204 pin SODIMM
Capacity 8GB 2 x 4GB Kit
Warranty Lifetime