diff --git a/src/SluDelayCalculator.py b/src/SluDelayCalculator.py
index 5158fc9ae208d33a75300ce8d717c9b707bfa791..1e018f41f1724141edf2c27b42513144d053e426 100644
--- a/src/SluDelayCalculator.py
+++ b/src/SluDelayCalculator.py
@@ -326,7 +326,7 @@ class MainWindow(QDialog):
         lo_scope6.addWidget(self.scope6clearswaps, 2, 4, 3, 1)
         self.grupposcope6.setLayout(lo_scope6)
         #
-        self.gruppotrls5 = QGroupBox("Totem delay line")
+        self.gruppotrls5 = QGroupBox("Totem delay line (positive movement ADD delay, negative movement REMOVE delay)")
         self.trls5_tasto = QPushButton('panel')
         self.trls5_tasto.clicked.connect(self.delaytotemapri)
         self.trls5_read = QLineEdit('')