Adamanta 16GB (1x16GB) Laptop Memory Upgrade for Lenovo Thinkpad W550s DDR3L 1600Mhz PC3L-12800 SODIMM 2Rx8 CL11 1.35v DRAM for Updated BIOS 16GB ( 16GBx1 ) 1600 Mhz Non-Parity/Non-ECC Unbuffered Memory 204pin Low Voltage DDR3L Dual Rank Module. BIOS must be updated to newest version for parts to be compatible. Every module is backed by a lifetime limited warranty. We always have hundreds in stock! Free technical support from our experienced technicians. Every single module is fully tested by the manufacturer. Our experienced technicians can verify if these parts will work for you.