Kingston Technology 4GB 1600MHz PC3-12800 1.35V SODIMM Memory for Select HP/Compaq Notebooks KTH-X3CL/4G One 4GB Module of 1600MHZ DDR3 Memory Backed by a lifetime warranty and free technical support From the industry leader in PC memory Designed and tested for compatibility in various HP/Compaq Notebooks 691740-001 (HP/Compaq)