Capacity: 64GB (2x32GB) --- Technology: DDR4 --- Speed: PC4-21300 2666MHz CL19 --- ECC Type: ECC Registered --- Form Factor: 288-Pin ECC DIMM (RDIMM) --- Voltage: 1.2V --- Backward Compatibility: Also compatible with 2400MHz and 2133MHz --- Replacement For: Dell A9781929, A9810563, A9810568, AB003150, SNPTN78YC/32G, SNPTN78YC/32VXR, TN78Y; Hynix HMA84GR7AFR4N‐VK, HMA84GR7CJR4N‐VK, HMA84GR7DJR4N‐VK, HMA84GR7JJR4N‐VK; Kingston KSM26RD4/32HDI, KSM26RD4/32MRR; Lenovo 4X70P98203, 7X77A01304; Micron MTA36ASF4G72PZ‐2G6; QNAP RAM-32GDR4ECK0-RD-2666; Samsung M393A4K40BB2‐CTD, M393A4K40CB2‐CTD, M393A4K40DB2‐CTD; Supermicro MEM-DR432LC-ER26, MEM‐DR432L‐CL01‐ER26, MEM‐DR432L‐CL02‐ER26, MEM‐DR432L‐CL03‐ER26, MEM‐DR432L‐CL05‐ER26, MEM‐DR432L‐HL01‐ER26, MEM‐DR432L‐HL03‐ER26, MEM‐DR432L‐SL02‐ER26, MEM‐DR432L‐SL03‐ER26, MEM‐DR432L‐SL04‐ER26; Synology D4ER01-32G, D4RD-2666-32G --- OWC DDR4 memory is Fully compliant with JEDEC specifications, ROHS compliant, providing a warranty safe upgrade. OWC Memory is the most cost effective and simple DIY upgrade you can install to unleash your Mac or PC's full potential and speed up overall responsiveness. Become a multitasking maven when you upgrade your Mac or PC with OWC Memory. Open more apps. Open larger files. Plus, work with multiple files all at the same time. We test every OWC memory module at our in house lab so you can upgrade with the confidence that your memory is built to last. We built your OWC Memory upgrade to meet or exceed the toughest industry specs to provide years of worry-free service. OWC recommends that all DIMMs be the same capacity, speed, and manufacturer to ensure optimal memory performance.