Why won't Apple's original 1TB SSD fit in my JDM 855/825 enclosure? Category : Compatibility To allow for higher capacity, Apple has widened the PCB for its 1TB SSDs, so that compared to Apple's other SSDs, the 1TB SSD comes larger in size. This is why the original 1TB SSD from Apple won't fit in the JetDrive 855/825 enclosure. Is the answer helpful? Related My newly installed JetDrive cannot be detected in Mac's Disk Utility. How can I enhance SSD performance if my operating system does not support TRIM? What is ''wear-out indicator'' in Transcend's JetDrive Toolbox? Technical Support If the answer can't help you, you can contact the Tech Support Department Get Started