Patriot Memory's Signature Line DDR3 1333 M Hz SODIMM for Apple computer systems delivers quality, reliability & performance that makes them the perfect memory upgrade solution. We test for compatibility in Apple i Mac, Mac Book, Mac Book Pro & Mac Pro systems. This 8GB kit (2 x 4GB) is designed to run at PC3-10600 (1333 M Hz) at CAS 9 latency timings. Built using specific build-of-materials (BOMs) we ensure that every module meets & exceeds industry standards: offering you a hassle-free upgrade. With free customer service & a lifetime warranty, Patriot Memory's Signature memory modules are a perfect system upgrade option.