An M.2 SSD is “keyed” to prevent insertion of a card connector (male) to an incompatible socket (female) on the host. The M.2 specification identifies 12 key IDs on the module card and socket interface but M.2 SSDs typically use three common keys: B, M, and B+M
M.2 Connector Guide on Keys and Sockets for SSDs
NVMe SSD Adapter Card for M.2, X4, (1x) M.2(M Key) and (1) M.2(B Key) connectors : Electronics
What Is The M.2 Expansion Slot? The Future Of Compact, Robust Technolo – Premio Inc
The M.2 interface
The M.2 interface
The M.2 interface
What Is The M.2 Expansion Slot? The Future Of Compact, Robust Technolo – Premio Inc
M.2 Connector Guide on Keys and Sockets for SSDs
How To Distinguish the Differences Between M.2 Cards
Demystifying M.2 Card Types
The M.2 interface
NVMe vs M.2 vs SATA vs PCIe: What are these SSDs?
Types of M.2 Drives & Slots (An In-Depth Guide)
What Is The M.2 Expansion Slot? The Future Of Compact, Robust Technolo – Premio Inc
M.2 Slot Types - ElectronicsHub