Wide compatibility Designed to house 4Raspberry Pi 4B, 3B/3B, or other B models, 42.5 SSDs and Ethernet switch in a cluster case. You can use it as a complete desktop NAS. It also has holes reserved for the SD card extension adapter (ASIN: B09CKRDFTH) which allows you to access the SD card from the front of the case. Please note that the thickness of a 2.5″ SSD cannot exceed 7mm.