diff --git a/Param/Node/INode.h b/Param/Node/INode.h
index 4308f60ed646102d6ee93bc3b1d2f709aa5425d2..fbd02ceb230616c7bd50abe9a8338f8784c02d2a 100644
--- a/Param/Node/INode.h
+++ b/Param/Node/INode.h
@@ -29,10 +29,10 @@ const double INF = std::numeric_limits<double>::infinity();
 struct ParaMeta {
     std::string name;
     std::string unit;
-    std::string tooltip;
-    double vMin;
-    double vMax;
-    double vDefault;
+    std::string tooltip {""};
+    double vMin {0};
+    double vMax {0};
+    double vDefault {0};
 };
 
 //! Base class for tree-like structures containing parameterized objects.
diff --git a/Sample/HardParticle/Box.h b/Sample/HardParticle/Box.h
index ce750de89c34075ed0749ea6614869553689403e..276834aeb5a1e80b6c45279243bfb418d1309e09 100644
--- a/Sample/HardParticle/Box.h
+++ b/Sample/HardParticle/Box.h
@@ -28,12 +28,12 @@ public:
 
     Box* clone() const override { return new Box(m_length, m_width, m_height); }
     std::string className() const final { return "Box"; }
-    // const auto tooltip = "rectangular cuboid";
+
     std::vector<ParaMeta> parDefs() const final
     {
-        return {{"Length", "nm", "side length in x direction", 0, +INF, 0},
-                {"Width", "nm", "side length in y direction", 0, +INF, 0},
-                {"Height", "nm", "side length in z direction", 0, +INF, 0}};
+        return {{"Length", "nm"},
+                {"Width", "nm"},
+                {"Height", "nm"}};
     }
 
     double length() const { return m_length; }