Works on Mac Pro A1289 and Mac pro A1481. Also tested and working in Mac Pro A1481 (2013), which accept 4 of these modules and supports 64GB. You are buying 32Gb Ram (2 x 16Gb Modules) which are fully tested working in Mac pro a1289 2010-2012 ( can support 48GB and 64GB depending on year and processor specs, I know all of them support 48GB any way).
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