M.2 formerly known as the Next Generation Form Factor (NGFF) is a specification for internally mounted computer expansion cards and associated connectors. The M.2 replaces the mSATA standard.
The M.2 interface on Helios64 only supports SATA 3.0 and USB 2.0 buses.
The M.2 SATA bus is shared with SATA Port 1. Therefore if you install an M.2 SATA SSD card, SATA Port 1 (J3) will automatically get disabled. But if you use the M.2 interface for USB modules, the SATA Port 1 (J3) is still enabled and accessible by the system.
For more details refer to [SATA page](/helios64/sata/).
!!! Note
The M.2 interface on Helios64 may NOT support USB modem (WWAN) because USB modem often requires external SIM Card connection and other signals.