16GB (2x8GB) DDR3 1333MHz PC3-10600 SODIMM for Apple MacBook Pro 2011 8, 1 8, 2 8, 3. Certified for all 2011 MacBook with Intel Core i5 i7, 13" 15"MD313LL/A, MC725LL/A CTO, i7 2.2GH z 17" MC725LL/A, i7 2.3GH z 15" MC723LL/A CTO, i7 2.2GH z 15" MC723LL/A, i7 2.0GH z 15" MC721LL/A, i7 2.7GH z 13" MC724LL/A, i5 2.3GH z 13" MC700LL/A Apple recommends two matching modules of the same size be installed for maximum performance. NEMIX RAM is backed by Lifetime Warranty.