diff --git a/Device-Models.md b/Device-Models.md
index b1b2a31..f1f0eda 100644
--- a/Device-Models.md
+++ b/Device-Models.md
@@ -1,5 +1,9 @@
 ## Supported device models
 
-### TUN
+### File Descriptor
+
+`-device fd://<fd_int>`
+
+### TUN Module
 
 `-device tun://<tun_name>`
\ No newline at end of file