diff --git a/source/_integrations/sfr_box.markdown b/source/_integrations/sfr_box.markdown
index 9460349ce11..9a1dbeec6f9 100644
--- a/source/_integrations/sfr_box.markdown
+++ b/source/_integrations/sfr_box.markdown
@@ -26,3 +26,9 @@ This integration provides the following platforms:
 - Sensors - such as ADSL line status, attenuation, noise and data rate.
 
 {% include integrations/config_flow.md %}
+
+## Compatibility
+
+The integration uses the REST API, which is known to be available on models `NB4`, `NB5`, `NB6`, `NB6V`, and `NB6VAC`.
+
+However, `NCC` models do not appear to expose this REST API, and are therefore unsupported by the integration.