Tested and working.
eBay
Crucial 4GB DDR3-1600 PC3-12800S 2Rx8 SODIMM
eBay
CT51264BF160B -MB. This will not affect functionality. Lenovo ThinkPad W550s, ThinkPad W530. Compatible with. If you receive a defective product, we will replace it with a working one or give your money back.
eBay
used, works as expected
eBay
New open Box memory ram
eBay
Crucial 8GB 2x4GB 204-Pin SODIMM DDR3 (PC3-12800) RAM 1.35V USA. Condition is Used. Shipped with USPS Ground Advantage.
eBay
eBay
The Crucial 4GB RAM Memory CT51264BF160B.C16FER2 is a set of two DDR3 SDRAM DIMM modules with a total capacity of 8GB. Each module has a capacity of 4GB, and they operate at a bus speed of PC3-12800
eBay