661-5096 Early 2009, Quad-Core, Processor, Mac Pro 2.66 GHz - Mac Pro A1289 Early 2009 NB-2053W
This is a single quad-core 2.66GHz processor for the Mac Pro (Early 2009).
Apple part number: 661-5096
Compatible models: A1289-Early 2009-MB871LL/A, A1289-Early 2009-MB535LL/A, A1289-Early 2009, A1289-Early 2009
Compatible Mac info. : 2.66GHz-2.93GHz-3.33GHz Quad-Core Mac Pro , 2.26GHz 8-Core Mac Pro , 2.66GHz 8-Core Mac Pro , 2.93GHz 8-Core Mac Pro
661-5096 Early 2009, Quad-Core, Processor, Mac Pro 2.66 GHz - Mac Pro A1289 Early 2009