32GB Kit ( 4 x 8GB Modules ) DDR3 1066/1067 MHz ( PC3-8500 ) DDR3 SO-DIMM ( 204-Pin ) Non-ECC Unbuffered Apple Mac Certified Memory RAM Upgrade Designed For Select Apple Mac Systems: iMac (for a complete list of compatible systems, see the description section) Compatible Apple Order Numbers: MB953LL/A / MC507LL/A Compatible Apple Model IDs: iMac11,1 Compatible Apple Model Numbers/EMC: A1312 (EMC 2374) A-Tech provides a Lifetime Warranty for all orders & offers complimentary United States based Tech Support before, during, & after your purchase