diff --git a/fixtracks/widgets/tracks.py b/fixtracks/widgets/tracks.py
index feb798f..2e48f58 100644
--- a/fixtracks/widgets/tracks.py
+++ b/fixtracks/widgets/tracks.py
@@ -14,6 +14,8 @@ from fixtracks.utils.writer import PickleWriter
 from fixtracks.widgets.detectionview import DetectionView, DetectionData
 from fixtracks.widgets.detectiontimeline import DetectionTimeline
 from fixtracks.widgets.skeleton import SkeletonWidget
+from fixtracks.widgets.classifier import ClassifierWidget
+
 
 class PoseTableModel(QAbstractTableModel):
     column_header = ["frame", "track"]
@@ -259,6 +261,10 @@ class DataController(QObject):
             logging.error("Column %s not in dictionary", col)
             return np.nan
 
+    @property
+    def numDetections(self):
+        return self._data["track"].shape[0]
+
     @property
     def selectionRange(self):
         return self._start, self._stop
@@ -286,6 +292,12 @@ class DataController(QObject):
     def assignUserSelection(self, track_id):
         self._data["track"][self._user_selections] = track_id
 
+    def assignTracks(self, tracks):
+        if len(tracks) != self.numDetections:
+            logging.error("DataController: Size of passed tracks does not match data!")
+            return
+        self._data["track"] = tracks
+
     def save(self, filename):
         export_columns = self._columns.copy()
         export_columns.remove("index")
@@ -299,6 +311,8 @@ class DataController(QObject):
             return 0
         return self._data["keypoints"][0].shape[0]
 
+    def coordinates(self):
+        return  np.stack(self._data["keypoints"]).astype(np.float32)
 
 class FixTracks(QWidget):
     back = Signal()
@@ -391,9 +405,13 @@ class FixTracks(QWidget):
         btnBox.addWidget(self._progress_bar)
         btnBox.addWidget(self._saveBtn)
 
+        self._classifier = ClassifierWidget()
+        self._classifier.apply_sizeclassifier.connect(self.on_classifyBySize)
+        self._classifier.setMaximumWidth(500)
         cntrlBox = QHBoxLayout()
-        cntrlBox.addItem(QSpacerItem(200, 100, QSizePolicy.Policy.Fixed, QSizePolicy.Policy.Expanding))
+        cntrlBox.addWidget(self._classifier)
         cntrlBox.addWidget(self._controls_widget, alignment=Qt.AlignmentFlag.AlignCenter)
+        cntrlBox.addItem(QSpacerItem(300, 100, QSizePolicy.Policy.Fixed, QSizePolicy.Policy.Expanding))
 
         vbox = QVBoxLayout()
         vbox.addLayout(timelinebox)
@@ -412,6 +430,12 @@ class FixTracks(QWidget):
         layout.addWidget(splitter)
         self.setLayout(layout)
 
+    def on_classifyBySize(self, tracks):
+        self._data.setSelectionRange("index", 0, self._data.numDetections)
+        self._data.assignTracks(tracks)
+        self._timeline.setDetectionData(self._data.data)
+        self.update()
+
     def on_dataSelection(self):
         filename = self._data_combo.currentText()
         if "please select" in filename.lower() or len(filename.strip()) == 0:
@@ -509,6 +533,8 @@ class FixTracks(QWidget):
             maxframes = self._data.max("frame")
             rel_width = self._windowspinner.value() / maxframes
             self._timeline.setWindowWidth(rel_width)
+            coordinates = self._data.coordinates()
+            self._classifier.size_classifier.setCoordinates(coordinates)
             self.update()
             self._saveBtn.setEnabled(True)