Key
ID	Notched
pins	Provided interfaces
A	8–15	2 of PCIe ×1, USB 2.0, I2C and DP ×4
B	12–19	PCIe ×2, SATA, USB 2.0 and 3.0, audio, UIM, HSIC, SSIC, I2C and SMBus
C	16–23	Reserved for future use
D	20–27
E	24–31	2 of PCIe ×1, USB 2.0, I2C, SDIO, UART, PCM and CNVi
F	28–35	Future Memory Interface (FMI)
G	39–46	Reserved for custom use (unused in the M.2 specification)
H	43–50	Reserved for future use
J	47–54
K	51–58
L	55–62
M	59–66	PCIe ×4, SATA and SMBus