diff --git a/README.md b/README.md
index 2d71f97..01be003 100644
--- a/README.md
+++ b/README.md
@@ -75,6 +75,13 @@ See `docs/harness` for wire harness diagram source.
 ![Diagram of the elevation rotator harness.](img/harness-rotator-el.png)
 *Diagram of the elevation rotator harness.*
 
+# Green Heron RT-21 Az/El Rotator Controller
+Green Heron RT-21 Az/El Rotator Controller.
+
+
+![Back Panel of Green Heron RT-21 Az/El Rotator Controller](img/greenheron-rt21-azel-back.png)
+*Back Panel of Green Heron RT-21 Az/El Rotator Controller*
+
 
 # SatNOGS
 *A global network of satellite ground stations, designed as an open source
diff --git a/img/greenheron-rt21-azel-back.png b/img/greenheron-rt21-azel-back.png
new file mode 100644
index 0000000..a451783
Binary files /dev/null and b/img/greenheron-rt21-azel-back.png differ