diff --git a/hyperspy_gui_traitsui/hyperspy_extension.yaml b/hyperspy_gui_traitsui/hyperspy_extension.yaml
index 927e0ab..a001b25 100644
--- a/hyperspy_gui_traitsui/hyperspy_extension.yaml
+++ b/hyperspy_gui_traitsui/hyperspy_extension.yaml
@@ -60,4 +60,7 @@ GUI:
         function: microscope_parameters_EDS_SEM
       hyperspy.microscope_parameters_EDS_TEM:
         module: hyperspy_gui_traitsui.microscope_parameters
-        function: microscope_parameters_EDS_TEM
\ No newline at end of file
+        function: microscope_parameters_EDS_TEM
+      hyperspy.EELSModel.estimate_and_set_coreloss_edge_onset:
+        module: hyperspy_gui_traitsui.model
+        function: estimate_and_set_coreloss_edge_onset_traitsui
diff --git a/hyperspy_gui_traitsui/model.py b/hyperspy_gui_traitsui/model.py
index 14cd46c..797084b 100644
--- a/hyperspy_gui_traitsui/model.py
+++ b/hyperspy_gui_traitsui/model.py
@@ -25,3 +25,26 @@ def fit_component_tratisui(obj, **kwargs):
         handler=ComponentFitHandler,
     )
     return obj, {"view": fit_component_view}
+
+
+class EstimateAndSetCorelossEdgeOnsetHandler(SpanSelectorInSignal1DHandler):
+
+    def fit(self, info):
+        """Handles the **Apply** button being clicked.
+
+        """
+        obj = info.object
+        obj._set_onset_fired()
+        return
+
+
+@add_display_arg
+def estimate_and_set_coreloss_edge_onset_traitsui(obj, **kwargs):
+    estimate_and_set_coreloss_edge_onset_view = tu.View(
+        tu.Item('percent_position', show_label=True,),
+        tu.Item('only_current', show_label=True,),
+        buttons=[OurFitButton, OurCloseButton],
+        title='Set edge onset',
+        handler=EstimateAndSetCorelossEdgeOnsetHandler,
+    )
+    return obj, {"view": estimate_and_set_coreloss_edge_onset_view}