The Collector USB Flash Drive Concept can put unused small micro SD cards to good use. It combines a number of small capacity memory Micro SD cards them into one use able USB memory flash drive.that's a nifty invention.
The Cluster HAT interfaces a (Controller) Raspberry Pi with 4 Raspberry Pi Zeros (NOT included). Configured to use USB Gadget mode, it is an ideal tool for teaching, testing or simulating small scale clusters.
ONE: Infografía: Todo lo que necesitas saber sobre Raspberry Pi