OWC 16.0GB (4 x4GB) PC8500 DDR3 1066 MHz 240 pin Memory Upgrade Kit for Apple iMac 21.5 inch and 27 inch Models, (OWC8566DDR3S16S) OWC Memory Upgrade Kit: 16.0GB (4x 4GB) PC8500 DDR3 Non ECC 1066 MHz 204 pin SO-DIMM High Quality 16.0 GB (4x 4GB) OWC Brand PC8500 DDR3 Non ECC 1066 MHz 204 pin SO-DIMM Memory upgrade kit For all Apple iMac 21.5" and 27" (October/2009) Models For all Apple iMac 21.5" and 27" (October/2009) Models, Compatible with PC desktops with Intel / AMD Process based PCs capable with the specifications listed above. Memory complies with JEDEC Specifications, document JESD79-3B Compatible with Mac systems: iMac 27-inch (Late 2009 Model ID:iMac10,1 and iMac11,1) iMac 21.5-inch (Late 2009 Model ID:iMac10,1) OWC Memory Lifetime Limited Warranty including Advanced Replacement Program iMac (27-inch Late 2009)(October, 2009) <span class="a-text-bold">Model ID:</span>iMac10,1; iMac11,1(2.66GHz, 2.8GHz, 3.06GHz, 3.33GHz) iMac (21.5-inch Late 2009)(October, 2009) <span class="a-text-bold">Model ID:</span>iMac10,1(3.06GHz, 3.33GHz) PC Laptops:Compatible with Intel / AMD Process based PCs capable with the specifications listed above <span class="a-text-bold"></span>Total of Four Memory Slots Install Pairs (2 at a time) for best performance Maximum of 16GB Total Memory Supported <span class="a-text-bold">Technology:</span>DDR3 SDRAM <span class="a-text-bold">Density:</span>4GB (4096MB) <span class="a-text-bold">RoHS:</span>Yes <span class="a-text-bold">Pin Count:</span>204-pin <span class="a-text-bold">Op. Temp.:</span>0C to +85C <span class="a-text-bold">Data Rate:</span>DDR3-1066 <span class="a-text-bold">Speed:</span>PC3-8500 <span class="a-text-bold">CL:</span>CL = 7 <span class="a-text-bold">Cycle Time:</span>1.875ns <span class="a-text-bold">Voltage:</span>1.5V <span class="a-text-bold">ECC:</span>Non ECC <span class="a-text-bold">Module Ranks:</span>Dual Rank <span class="a-text-bold">Register:</span>Non Parity Low Noise 8-Layer PCB Meets and/or Exceeds Apple/Intel Specifications Fully compliant with JEDEC specifications