Apple Computer, Mac Pro 2.7 GHz 'Quad Core', Mac Pro 3.5 GHz ' Six Core', Mac Pro 3.0 GHz 'Eight Core', Mac Pro 2.7 GHz 'Twelve Core', Apple Order Number, ME253LL/A, MD878LL/A, BTO/CTO, Model Number, A1481, Model Year, Late 2013, Part Name, CPU Riser Card 3.5 GHz (6-Core), Manufacture Part Number, 820-5494-A, Compatible Apple Order Number, ME253LL/A, MD878LL/A, BTO/CTO, Compatible Model Number, A1481, EMC Number, EMC-2630, EEE Code, N/A, Compatible Apple Computer Family, Mac Pro (Late 2013)
Order you product here: 661-7545 CPU Riser Card 3.5 GHz (6-Core) for Mac Pro Late 2013 A1481 ME253LL/A, MD878LL/A, BTO/CTO (820-5494-A), 661-7545
source http://info.applepartsellers.com/661-7545-cpu-riser-card-3-5-ghz-6-core-for-mac-pro-late-2013-a1481-me253ll-a-md878ll-a-bto-cto-820-5494-a