Please must upgrade the host MAC to macOS 10.13 High Sierra (or 10.14 Mojave or 10.15 Catalina) before replacing the new SSD. How to use? Create USB Bootable Installer 1, Download macOS 10.13 or later to create a bootable installer into USB drive. 2, Replace the new SSD to MAC computer. 3, Connect USB Bootable Installer to Mac, start Mac and hold the "Option" key during startup. Select and click "Install macOS xxx". 4, Select "Disk Utility" to format (Erase) SSD from "macOS Utilities". 5, Select "Reinstall macOS" from "macOS Utilities", then follow the prompts to install macOS into new SSD. Universal Compatibility: For MacBook Pro 13 inch: Late 2013: A1502, EMC 2678, MacbookPro11,1; Mid 2014: A1502, EMC 2875, MacbookPro11,1; Early 2015: A1502, EMC 2835, MacbookPro12,1 15 inch: Late 2013: A1398, EMC 2674, MacbookPro11,2 MacbookPro11,3; Mid 2014: A1398, EMC 2876 EMC 2881, MacbookPro11,2 MacbookPro11,3; Mid 2015: A1398, EMC 2909 EMC 2910, MacbookPro11,4 MacbookPro11,5; For MacBook Air 11 inch: Mid 2013, Early 2014: A1465, EMC 2631, MacbookAir6,1; Early 2015: A1465, EMC 2924, MacbookAir7,1; 13 inch: Mid 2013, Early 2014: A1466 EMC 2632, MacbookAir6,2; Early 2015, A1466: EMC 2925, MacbookAir7,2; 2017: A1466, EMC 3178, MacbookAir7,2 For iMac 21.5 inch: Late 2013: A1418, EMC 2638, iMac14,1 iMac14,3; Mid 2014: A1418, EMC 2805, iMac14,4; Late 2015: A1418, EMC 2889, iMac16,1; EMC 2883 iMac16,2; 2017: A1418, iMac18,1; 2017 Retina 4K: A1418, EMC 3069, iMac18,2 27 inch: Late 2013: A1419, EMC 2639, iMac14,2; Late 2014, Mid 2015: A1419, EMC 2806, iMac15,1; Late 2015: A1419, EMC 2834, iMac17,1; 2017 Retina 5K: A1419, EMC 3070, iMac18,3; For Mac Mini & Mac Pro Mac mini: 2014: A1347; Macmini7,1 Mac Pro: 2013: A1481; MacPro6,1 ... More