An M.2 SSD to USB 3.1 external case is a portable adapter that turns your internal M.2 drive (NVMe or SATA) into a super-fast external drive, using a USB 3.1 (Gen 2, 10Gbps) interface for speeds over 900MB/s, featuring tool-free installation, durable aluminum heat dissipation, and compatibility with Windows/Mac/Linux for fast data backup or expanding storage without drivers, often using a USB-C port.