PCI Express M.2 Specification Revision 1.1

The M.2 form factor is intended for Mobile Adapters. The M.2 is a natural transition from the Mini 3 Card and Half-Mini Card (refer to the PCI Express Mini CEM Specification) to a smaller form factor in 4 both size and volume. The M.2 is a family of form factors that enables expansion, contraction, and 5 higher integration of functions onto a single form factor module solution.

PCI Express
1.x
Specification
Member
https://members.pcisig.com/wg/PCI-SIG/document/download/10029