diff --git a/README.md b/README.md
index a78dc5c..8df3fcc 100644
--- a/README.md
+++ b/README.md
@@ -401,6 +401,8 @@ some ops make a circle do things to its targets. like `process`, `del_targets`,
     - when color changes, set the color of the selection lasso circle (and draw mode indicator)
 - `connection_color`
     - when color changes, set the color of connection arrows
+- `connection_width`
+    - when this circle's num changes, set the width of the connection arrows
 - `connecting_line_color`
     - when color changes, set the connect mode indicator
 - `command_color`
diff --git a/src/components.rs b/src/components.rs
index 1401bb8..6e97a2d 100644
--- a/src/components.rs
+++ b/src/components.rs
@@ -237,6 +237,10 @@ pub struct ConnectionColor(pub Color);
 #[reflect(Resource)]
 pub struct CommandColor(pub Color);
 
+#[derive(Resource, Reflect, Default)]
+#[reflect(Resource)]
+pub struct ConnectionWidth(pub f32);
+
 #[derive(Resource)]
 pub struct DefaultLT(pub (i8, i8));
 
diff --git a/src/connections.rs b/src/connections.rs
index 76e2244..86783b5 100644
--- a/src/connections.rs
+++ b/src/connections.rs
@@ -174,6 +174,7 @@ pub fn update_connection_arrows(
     trans_query: Query<&Transform, With<Vertices>>,
     mut arrow_trans: Query<&mut Transform, Without<Vertices>>,
     arrow_query: Query<&ConnectionArrow>,
+    connection_width: Res<ConnectionWidth>,
 ) {
     for (id, bh) in bh_query.iter() {
         if wh_query.contains(bh.wh) { continue; }
@@ -189,7 +190,7 @@ pub fn update_connection_arrows(
                 let f = bh_trans + bh_radius * norm;
                 *arrow_trans.get_mut(arrow_id.0).unwrap() = Transform {
                     translation: ((i+f) / 2.).extend(100.),
-                    scale: Vec3::new(4., wh_trans.distance(bh_trans) - (bh_radius + wh_radius), 1.),
+                    scale: Vec3::new(connection_width.0, wh_trans.distance(bh_trans) - (bh_radius + wh_radius), 1.),
                     rotation: Quat::from_rotation_z(perp.to_angle()),
                 };
             }
@@ -208,7 +209,7 @@ pub fn update_connection_arrows(
                 let f = bh_trans + bh_radius * norm;
                 *arrow_trans.get_mut(arrow_id.0).unwrap() = Transform {
                     translation: ((i+f) / 2.).extend(100.),
-                    scale: Vec3::new(4., wh_trans.distance(bh_trans) - (bh_radius + wh_radius), 1.),
+                    scale: Vec3::new(connection_width.0, wh_trans.distance(bh_trans) - (bh_radius + wh_radius), 1.),
                     rotation: Quat::from_rotation_z(perp.to_angle()),
                 };
             }
diff --git a/src/main.rs b/src/main.rs
index 76c968c..c64c4e1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -64,6 +64,7 @@ fn main() {
     .insert_resource(DefaultDrawVerts(4))
     .insert_resource(HighlightColor(Color::hsl(0.0,1.0,0.5)))
     .insert_resource(ConnectionColor(Color::hsla(0., 1., 1., 0.7)))
+    .insert_resource(ConnectionWidth(4.))
     .insert_resource(CommandColor(Color::hsla(0., 0., 0.7, 1.)))
     .insert_resource(DefaultLT((0, 0)))
     .insert_resource(SystemClipboard(ClipboardContext::new().unwrap()))
@@ -150,6 +151,7 @@ fn main() {
     .register_type::<DefaultDrawVerts>()
     .register_type::<HighlightColor>()
     .register_type::<ConnectionColor>()
+    .register_type::<ConnectionWidth>()
     .register_type::<CommandColor>()
     .register_type::<Version>()
     .register_type::<Holes>()
@@ -292,6 +294,7 @@ fn save_scene(world: &mut World) {
             .allow_resource::<DefaultDrawVerts>()
             .allow_resource::<HighlightColor>()
             .allow_resource::<ConnectionColor>()
+            .allow_resource::<ConnectionWidth>()
             .allow_resource::<ClearColor>()
             .allow_resource::<CommandColor>()
             .allow_resource::<Version>()
diff --git a/src/process.rs b/src/process.rs
index 5f35da5..94b1e8c 100644
--- a/src/process.rs
+++ b/src/process.rs
@@ -83,6 +83,8 @@ pub struct Access<'w, 's> {
     default_verts: ResMut<'w, DefaultDrawVerts>,
     highlight_color: ResMut<'w, HighlightColor>,
     connection_color: ResMut<'w, ConnectionColor>,
+    connection_width: ResMut<'w, ConnectionWidth>,
+    arrow_query: Query<'w, 's, &'static ConnectionArrow>,
     selection_circle: Res<'w, SelectionCircle>,
     connecting_line: Res<'w, ConnectingLine>,
     command_line_text: Query<'w, 's, &'static mut Text, With<CommandText>>,
@@ -707,6 +709,14 @@ pub fn process(
                 let clt = &mut access.command_line_text.single_mut();
                 clt.sections[0].style.color = color.0;
             }
+        } else if op == "connection_width" {
+            let n = access.num_query.get_mut(*id).unwrap();
+            if n.is_changed() {
+                access.connection_width.0 = n.0;
+                for e in access.arrow_query.iter() {
+                    access.trans_query.get_mut(e.0).unwrap().scale.x = n.0;
+                }
+            }
         } else if op == "tonemapping" {
             let mut tm = access.tonemapping.single_mut();
             for hole in holes {