Patriot's Signature Line DDR4 SODIMM memory delivers the quality, reliability and performance expected for today's notebook needs. This 4GB module is designed to run at 2666MHz (PC4-21300) at CAS 19 latency timings. Patriot memory is built using specific build-of-materials (BOMs) ensuring you that every module meets and exceeds industry standards: offering you a hassle-free upgrade. We certify every component that goes into our modules, including the modules themselves, which must pass strict standards to ensure compatibility, quality and reliability. With free customer service and a lifetime warranty, Patriot Memory's Signature memory modules are a perfect system upgrade option.