The ONE M.2 expansion board extends support for SATA M.2 SSDs to maximize the actual potential speeds of your 4. Now you can boot through a SATA M.2 SSD for faster boot time and higher storage capacity compared to traditional microSD card. To use it, you just need to replace the bottom of the with the expansion board, and the case can now use SSD. Using 4 cases is recommended due to the USB 3.0 ports provided by the boards. ONE M.2 supports UASP for 4, which means that you can maximize the transfer speeds of your SATA M.2 drive. It is compatible with any M.2 SATA SSD with Key-B and Key B & M. (not for NVME) colour: black Material: aluminum alloy The lower left corner is the product batch number, different batches have different numbers Package Contents: 4 x M.2 expansion board 4 x USB 3.0 adapter 16 x non-slip gaskets 16 x screws Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.