Important 1、Please do not purchase this SSD before confirming compatibility if your machine is not listed as compatible. 2、Before replacing our hard drive, please upgrade the MacOS to 10.13 or later using the original hard drive provided. Otherwise, the new solid-state drive may not be recognized. It is recommended to upgrade to 10.15 or above. If it is lower than 10.15, the macOS on the new solid-state drive will not be able to be upgraded to newer versions. 3、Upgrading the system is to upgrade the EFI firmware of the motherboard, so that it can recognize the new NVMe solid-state drives after the update. 4、If your previous MacOS version is 10.12 or below, and your original solid-state drive happens to be broken, then this hard drive is not suitable for direct use. You can only use the original solid-state drive or purchase an additional original 128G solid-state drive to upgrade the Apple system (available in our store). 5、This solid-state drive does not support MacOS lower than 10.13, as well as Windows 7 and Windows 8.