diff --git a/shelf.scad b/shelf.scad
index c748f7f..f75cc92 100644
--- a/shelf.scad
+++ b/shelf.scad
@@ -13,27 +13,47 @@ module arm() {
     cube([80, 400, 200]);
 }
 
-color("#999999")
-arm();
-
-module shelf() {
+module base() {
     translate([0, 0, -6])
     linear_extrude(15) {
         polygon(polyRound([
-            [-90, -40, 10],
-            [ 90, -40, 10],
-            [ 90,  40, 10],
-            [-90,  40, 10],
+            [-55, -40, 10],
+            [ 55, -40, 10],
+            [ 55,  40, 10],
+            [-55,  40, 10],
         ]));
     }
 }
 
+module grip(length) {
+    translate([40, 0, 0])
+    rotate([-90, 0, 0])
+    linear_extrude(15, center=true)
+    polygon(polyRound([
+        [ 0,  0, 0],
+        [10,  0, 0],
+        [10, length, 10],
+        [ 0, length, 0],
+    ]));
+}
+
 translate([0, 0, 6]) {
     difference() {
-        shelf();
+        base();
         cylinder(100, 35, 35);
     }
+    
+    grip(30);
+    
+    rotate([0, 0, 180])
+    grip(60);
 
+    if($preview)
+    color("#999999") {
+        arm();
+    }
+
+    if($preview)
     color("#7777ff") {
         *jar();
         cup();