8GB 2 X 4GB DDR3 SODIMM 1066MHz PC3-8500 204 pin Lenovo ThinkPad X200, X200s, X201, x201i, X201s, X301 Laptop Memory RAM (PARTS-QUICK BRAND) Halogen Free; ROHS Speed: PC3-8500 DDR3 1066MHz Form Factor: 204 pin SODIMM Capacity: 8GB 2 x 4GB Kit Warranty: Lifetime