diff --git a/csiborgtools/flow/flow_model.py b/csiborgtools/flow/flow_model.py
index 1e8c2b6..5000176 100644
--- a/csiborgtools/flow/flow_model.py
+++ b/csiborgtools/flow/flow_model.py
@@ -610,6 +610,8 @@ def sample_calibration(Vext_min, Vext_max, Vmono_min, Vmono_max, beta_min,
 
     if no_Vext:
         Vext = jnp.zeros(3)
+        # 840 in the direction of (l, b) = (117, 4)
+        # Vext = jnp.asarray([338.9478154 , -11.45056064, 768.49415294])
     else:
         Vext = sample("Vext", Uniform(Vext_min, Vext_max).expand([3]))