64GB ( 1 x 64GB Module ) DDR4 2666/2667 MHz ( PC4-21300 ) DDR4 RDIMM ( 288-Pin ) ECC Registered Apple Mac Certified Memory RAM Upgrade Designed For Select Apple Mac Systems: iMac Pro (for a complete list of compatible systems, see the description section) Compatible Apple Order Numbers: MQ2Y2LL/A Compatible Apple Model IDs: iMacPro1,1 Compatible Apple Model Numbers/EMC: A1862 (EMC 3144) A-Tech provides a Lifetime Warranty for all orders & offers complimentary United States based Tech Support before, during, & after your purchase