I have had the same happen to me with Toshiba MicroSD cards. I ended up returning them. I also bought a Transcend 128GB USB stick, which i unfortunately did no

I have had the same happen to me with Toshiba MicroSD cards. I ended up returning them. I also bought a Transcend 128GB USB stick, which i unfortunately did not return (yet). I have communicated with Transcend support and they said it was an issue with partitioning and filesystems - which is wrong, because the tools i use show the capacity at a lower level. They kept stubbornly repeating these statements. I may end up returning it which shouldn't be a problem even after almost 2 years because the defect has been there since the beginning. Here's what diskutil has to say about it: % diskutil info /dev/disk4 Device Identifier: disk4 Device Node: /dev/disk4 Whole: Yes Part of Whole: disk4 Device / Media Name: Transcend 128GB Disk Size: 123.7 GB (123718336512 Bytes) (exactly 241637376 512-Byte-Units) Device Block Size: 512 Bytes For comparison, i get this for a Lexar 32GB USB stick: Disk Size: 32.0 GB (32008830976 Bytes) (exactly 62517248 512-Byte-Units) You can clearly see that more than 4GB are missing on the Transcend 128GB stick. It should be around 119.2GiB (128GB) but it is 115.2GiB (123.7GB)