8GB Kit ( 4 x 2GB Modules ) DDR3 1333 MHz ( PC3-10600 ) 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: MC309LL/A / MC812LL/A / MC813LL/A / MC814LL/A / MD063LL/A / MC978LL/A / MC508LL/A / MC509LL/A / MC510LL/A / MC511LL/A / MC784LL/A Compatible Apple Model IDs: iMac11,2 / iMac11,3 / iMac12,1 / iMac12,2 Compatible Apple Model Numbers/EMC: A1311 (EMC 2389) / A1312 (EMC 2390) / A1311 (EMC 2428) / A1312 (EMC 2429) A-Tech provides a Lifetime Warranty for all orders & offers complimentary United States based Tech Support before, during, & after your purchase