Full Details from Amazon.com : http://www.amazon.com/gp/product/B00JIJU9YG?tag=onigi-20Transcend 16 GB DDR3-1866 ECC unbuffered DIMM 1Rx8 TS16GJMA545H (4GBx4 | Mac Pro Late 2013ECC DIMM 512Mx8 bit 1866 Mbps 15V Timing 13-13-13 1 Rank