Waveshare Argon One M.2 Aluminum Case For Raspberry Pi 4, with M.2 Expansion SlotAbout The Protuct The PI4 CASE ARGON ONE M. 2 metal case can greatly speed up the boot and storage speed of the Raspberry Pi, which is to extend the M. 2 interface through the USB interface and use an external SSD as the main storage drive. In this case, the Raspberry Pi 4 can be booted through the USB interface, which greatly improves the reading and writing speed and makes the boot speed much faster than using the SD card. Features 1. Aluminum alloy