diff --git a/res/CMakeLists.txt b/res/CMakeLists.txt
index 2862b5f4..204a2981 100644
--- a/res/CMakeLists.txt
+++ b/res/CMakeLists.txt
@@ -255,6 +255,7 @@ add_resources(
     icons/graphics-window/pointonx.png
     icons/graphics-window/point.png
     icons/graphics-window/rectangle.png
+    icons/graphics-window/relation.png
     icons/graphics-window/ref.png
     icons/graphics-window/revolve.png
     icons/graphics-window/same-orientation.png
diff --git a/res/icons/graphics-window/relation.png b/res/icons/graphics-window/relation.png
new file mode 100644
index 00000000..e60900c1
Binary files /dev/null and b/res/icons/graphics-window/relation.png differ
diff --git a/src/drawconstraint.cpp b/src/drawconstraint.cpp
index 3facb662..a62e6c01 100644
--- a/src/drawconstraint.cpp
+++ b/src/drawconstraint.cpp
@@ -28,9 +28,9 @@ std::string Constraint::Label() const {
     }
     if(expression != "") {
         result = expression ;
-			  if(SS.MmPerUnit() != expr_scaling_to_base) {
-					result += "*" + std::to_string(expr_scaling_to_base/SS.MmPerUnit());
-				}
+        if(SS.MmPerUnit() != expr_scaling_to_base && expr_scaling_to_base != 0) {
+            result += "*" + std::to_string(expr_scaling_to_base/SS.MmPerUnit());
+        }
     }
     if(reference) {
         result += " REF";
diff --git a/src/graphicswin.cpp b/src/graphicswin.cpp
index e2a252db..7f793d16 100644
--- a/src/graphicswin.cpp
+++ b/src/graphicswin.cpp
@@ -165,7 +165,7 @@ const MenuEntry Menu[] = {
 { 1, N_("Lock Point Where &Dragged"),   Command::WHERE_DRAGGED,    ']',     KN, mCon   },
 { 1, NULL,                              Command::NONE,             0,       KN, NULL   },
 { 1, N_("Comment"),                     Command::COMMENT,          ';',     KN, mCon   },
-{ 1, N_("Relation"),                    Command::RELATION,         ':',     KN, mCon   },
+{ 1, N_("Relation"),                    Command::RELATION,         '/',     KN, mCon   },
 
 { 0, N_("&Analyze"),                    Command::NONE,             0,       KN, mAna   },
 { 1, N_("Measure &Volume"),             Command::VOLUME,           C|S|'v', KN, mAna   },
diff --git a/src/toolbar.cpp b/src/toolbar.cpp
index 74764883..6152a541 100644
--- a/src/toolbar.cpp
+++ b/src/toolbar.cpp
@@ -62,6 +62,8 @@ static ToolIcon Toolbar[] = {
       N_("Other supplementary angle"),                        {} },
     { "ref",             Command::REFERENCE,
       N_("Toggle reference dimension"),                       {} },
+    { "relation",        Command::RELATION,
+      N_("Constrain variables with equation"),                {} },
     { "",                Command::NONE, "",                   {} },
 
     { "extrude",         Command::GROUP_EXTRUDE,