Design for Raspberry Pi: Supports installation of 4 Raspberry Pis and 4 ssds, compatible with any 2.5 Solid State Drive (7mm/9mm) and Rpi 4B/3B+, and other B/B+ models. The SSD mounting bracket also has two holes reserved for the SD card extension adapter ASIN: B09CKRDFTH, which allows you to access the SD card from the front of the rack. Easy to Setup: Just use two included thumbscrews to mount the rackmount, which adopts a screw-in design, which helps you install and replace quickly and easily, no tools needed! Applications: This is a hardware solution to get ingenious use of the Raspberry Pi, with this kit and open source software OpenMediaVault, you can use the Pi as a NAS Server, Surveillance station, or even a Web server. Optional accessories: Single mounting bracket: B09GFQLPTY; Micro SD card extension adapter ASIN: B09CKRDFTH. I/O Panel: B09FXRQPFM