diff --git a/fitspy/apps/pyside/__init__.py b/fitspy/apps/pyside/__init__.py
index be67dc3..617f109 100644
--- a/fitspy/apps/pyside/__init__.py
+++ b/fitspy/apps/pyside/__init__.py
@@ -6,6 +6,8 @@
     'ncpus': 'Auto',
     'outliers_coef': 1.5,
     'click_mode': 'highlight',
+    'dx0': 20,
+    'dfwhm': 200,
     'peaks_cmap': 'tab10',
     'map_cmap': 'viridis',
     'figure_options': {'title': 'DEFAULT_TITLE (edit in toolbar)'},
diff --git a/fitspy/apps/pyside/components/plot/model.py b/fitspy/apps/pyside/components/plot/model.py
index fef7a2b..1719010 100644
--- a/fitspy/apps/pyside/components/plot/model.py
+++ b/fitspy/apps/pyside/components/plot/model.py
@@ -248,7 +248,7 @@ def add_peak_point(self, ax, model, x, y):
             if dist < dist_min:
                 dist_min, ind_min = dist, ind
 
-        first_spectrum.add_peak_model(model, x0=x_sp[ind_min])
+        first_spectrum.add_peak_model(model, x0=x_sp[ind_min], dx0=DEFAULTS['dx0'], dfwhm=DEFAULTS['dfwhm'])
         self.PeaksChanged.emit(first_spectrum)
         self.refreshPlot.emit()
 
diff --git a/fitspy/apps/pyside/components/settings/controller.py b/fitspy/apps/pyside/components/settings/controller.py
index 9fad915..45b7b62 100644
--- a/fitspy/apps/pyside/components/settings/controller.py
+++ b/fitspy/apps/pyside/components/settings/controller.py
@@ -134,6 +134,10 @@ def setup_connections(self):
             lambda cmap: self.settingChanged.emit("peaks_cmap", cmap.name.split(":")[1]))
         self.other_settings.map_cmap.currentColormapChanged.connect(
             lambda cmap: self.settingChanged.emit("map_cmap", cmap.name.split(":")[1]))
+        self.other_settings.dx0.valueChanged.connect(
+            lambda value: self.settingChanged.emit("dx0", value))
+        self.other_settings.dfwhm.valueChanged.connect(
+            lambda value: self.settingChanged.emit("dfwhm", value))
 
     def load_default_models(self):
         HOME = Path.home()
diff --git a/fitspy/apps/pyside/components/settings/more_settings.py b/fitspy/apps/pyside/components/settings/more_settings.py
index 4002089..09fe3b9 100644
--- a/fitspy/apps/pyside/components/settings/more_settings.py
+++ b/fitspy/apps/pyside/components/settings/more_settings.py
@@ -4,7 +4,7 @@
 from superqt.cmap import CmapCatalogComboBox
 
 from fitspy import FIT_METHODS, FIT_PARAMS
-
+from fitspy.apps.pyside import DEFAULTS
 from fitspy.apps.pyside.components.settings.custom_spinbox import SpinBox, DoubleSpinBox
 
 
@@ -135,7 +135,6 @@ def initUI(self):
 
         # Peaks Colormap Selection
         hbox = QHBoxLayout()
-
         hbox.addWidget(QLabel("Peaks Colormap:"))
         # https://pyapp-kit.github.io/superqt/widgets/colormap_catalog/
         # https://cmap-docs.readthedocs.io/en/stable/catalog/#colormaps-by-category
@@ -145,12 +144,27 @@ def initUI(self):
 
         # 2D Map Colormap Selection
         hbox = QHBoxLayout()
-
         hbox.addWidget(QLabel("2D Map Colormap:"))
         self.map_cmap = CmapCatalogComboBox()
         hbox.addWidget(self.map_cmap)
         vbox.addLayout(hbox)
 
+        # dx0
+        hbox = QHBoxLayout()
+        hbox.addWidget(QLabel("X0 Bounds (±):"))
+        self.dx0 = DoubleSpinBox()
+        self.dx0.setValue(DEFAULTS["dx0"])
+        hbox.addWidget(self.dx0)
+        vbox.addLayout(hbox)
+
+        # dfwhm
+        hbox = QHBoxLayout()
+        hbox.addWidget(QLabel("FWHM Max (0/+):"))
+        self.dfwhm = DoubleSpinBox()
+        self.dfwhm.setValue(DEFAULTS["dfwhm"])
+        hbox.addWidget(self.dfwhm)
+        vbox.addLayout(hbox)
+
         self.setLayout(vbox)
 
 
diff --git a/fitspy/apps/pyside/main_controller.py b/fitspy/apps/pyside/main_controller.py
index e398ca0..a0ea60c 100644
--- a/fitspy/apps/pyside/main_controller.py
+++ b/fitspy/apps/pyside/main_controller.py
@@ -54,6 +54,8 @@ def setup_connections(self):
         self.model.defaultsRestored.connect(self.apply_settings)
         self.model.peaksCmapChanged.connect(self.update_peaks_cmap)
         self.model.mapCmapChanged.connect(self.update_map_cmap)
+        self.model.dx0Changed.connect(lambda: DEFAULTS.update({"dx0": self.model.dx0}))
+        self.model.dfwhmChanged.connect(lambda: DEFAULTS.update({"dfwhm": self.model.dfwhm}))
 
         self.files_controller.showToast.connect(self.show_toast)
         self.files_controller.askConfirmation.connect(self.show_confirmation_dialog)
@@ -123,6 +125,8 @@ def apply_settings(self):
         self.view.more_settings.other_settings.outliers_coef.setValue(self.model.outliers_coef)
         self.view.more_settings.other_settings.peaks_cmap.setCurrentText(self.model.peaks_cmap)
         self.view.more_settings.other_settings.map_cmap.setCurrentText(self.model.map_cmap)
+        self.view.more_settings.other_settings.dx0.setValue(self.model.dx0)
+        self.view.more_settings.other_settings.dfwhm.setValue(self.model.dfwhm)
 
         radio_button = getattr(self.view.toolbar, f"{self.model.click_mode}_radio")
         radio_button.setChecked(True)
diff --git a/fitspy/apps/pyside/main_model.py b/fitspy/apps/pyside/main_model.py
index 417dcd8..6e23108 100644
--- a/fitspy/apps/pyside/main_model.py
+++ b/fitspy/apps/pyside/main_model.py
@@ -9,6 +9,8 @@ class MainModel(QObject):
     peaksCmapChanged = Signal()
     mapCmapChanged = Signal()
     defaultsRestored = Signal()
+    dx0Changed = Signal()
+    dfwhmChanged = Signal()
 
     def __init__(self):
         super().__init__()
@@ -32,6 +34,8 @@ def _initialize_settings(self):
             "theme": self.themeChanged,
             "peaks_cmap": self.peaksCmapChanged,
             "map_cmap": self.mapCmapChanged,
+            "dx0": self.dx0Changed,
+            "dfwhm": self.dfwhmChanged,
         }
 
         def create_setting(default, type, signal=None):