> For the complete documentation index, see [llms.txt](https://bananapi.gitbook.io/banana-pi-bpi-w2-with-realtec-rtd1296/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://bananapi.gitbook.io/banana-pi-bpi-w2-with-realtec-rtd1296/chapter1/bpi-m2-m2-interface.md).

# BPI-W2 M.2 interface

BPI-W2 have 1 M.2 KEY B: USB 2.0 interface , so you can add USB standard 4G module on BPI-R2 . so support 4G function.