diff --git a/backpack-organization/main-box.scad b/backpack-organization/main-box.scad
index c64e8bc..4bac4a1 100644
--- a/backpack-organization/main-box.scad
+++ b/backpack-organization/main-box.scad
@@ -5,7 +5,7 @@ $fn=128;
 outerWall=4;
 innerWall=2;
 layerClearance = 0.5;
-verStr="v5";
+verStr="v6";
 font="Montserrat";
 
 // as a convention, outer dimensions refer to measurements from outside wall to
@@ -48,13 +48,17 @@ module audioLayer() {
         translate([handleDia / 2, handleDia / 2, handleDia / 2])
           cylinder(d=handleDia, h = handleDia / 2 + innerWall);
 
+        translate([(handleDia - 32) / 2, handleDia / 2, 7]) cube([32, 130 + handleDia/2, iH]);
+
         // screw bits
         bitL = 112;
-        bitW = 20;
+        bitW = 22;
         translate([(handleDia - bitW) / 2, handleDia / 2, 0]) cube([bitW, bitL + handleDia/2, iH]);
         // release ramp
-        translate([(handleDia - bitW)/2, handleDia/2 + bitW + bitL + 1, 0])
+        /*
+        translate([(handleDia - bitW)/2, handleDia/2 + 20 + bitL + 1, 0])
           rotate([-45, 0, 0]) translate([0, -iH, 0]) cube([bitW, iH, iH*2]);
+        */
 
         // lower-right cubby
         translate([handleDia + 2*innerWall, 0, 0])
@@ -70,11 +74,11 @@ module audioLayer() {
       //translate([innerWall, innerWall, innerWall]) cube([iW, iL, iH]);
     }
 
-    translate([handleDia*0.916, 69.5, -0.1])
-      cylinder(d=15, iH - innerWall + 0.1);
+    translate([handleDia*0.988, 69.5, -0.1])
+      cylinder(d=9, iH - innerWall + 0.1);
 
-    translate([handleDia*0.916, 105.5, -0.1])
-      cylinder(d=15, iH - innerWall + 0.1);
+    translate([handleDia*0.988, 105.5, -0.1])
+      cylinder(d=9, iH - innerWall + 0.1);
 
     translate([iW/2 - audioTraySide/2, iL - audioTraySide/2 - cableDia/2 - innerWall, 0])
     difference() {
@@ -100,8 +104,6 @@ module audioTrayBlank(s, h) {
             s - 2*(innerWall + layerClearance),
             h - 1],
           [1, 1, 1]);
-
-
     }
 
     // bottom edge chamfers
@@ -138,7 +140,7 @@ module audioTrayBlank(s, h) {
 
 module audioTray1() {
   difference() {
-    audioTrayBlank(s = audioTraySide, h = 15);
+    audioTrayBlank(s = audioTraySide, h = audioTrayHeight);
 
     translate([2.5, innerWall, innerWall])
     union() {
@@ -236,7 +238,7 @@ module audioTray2() {
 
 module audioTray3() {
   difference() {
-    audioTrayBlank(s = audioTraySide, h = audioTrayHeight - 2);
+    audioTrayBlank(s = audioTraySide, h = audioTrayHeight - 1);
 
     translate([2*innerWall, (audioTrayIS - 43)/2, innerWall])
       cube([43, 43, audioTrayIH]);
@@ -249,8 +251,79 @@ module audioTray3() {
   }
 }
 
+module usbBitsTray() {
+  difference() {
+    audioTrayBlank(s = audioTraySide, h = audioTrayHeight);
+
+    translate([innerWall, innerWall, innerWall])
+    union() {
+
+      // right-angle connectors (1st variation)
+      translate([innerWall, innerWall, -1])
+      for (i = [0, 1]) {
+        translate([33*i, 16*i, 0])
+        rotate([0, 0, 180*i])
+        union() {
+          // main body
+          cube([22, 7, 14]);
+
+          // usb connector
+          // 1.64 to edge, 4.64 thick
+          translate([1.4, 0, 0]) cube([5.2, 16, 14]);
+
+          // release wedge
+          translate([22, 0, 0])
+          rotate([0, 15, 0])
+          translate([-22, 0, 0])
+          cube([22, 7, 14]);
+
+          // fingerway
+          translate([-1, -1, 11])
+          cube([36, 18, 3]);
+        }
+      }
+
+      // right-angle connectors (2nd variation)
+      translate([innerWall, innerWall + 18, 5 + 0.1])
+      for (i = [0, 1]) {
+        translate([30*i, 36*i, 0])
+        rotate([0, 0, 180*i])
+        union() {
+          // main body
+          cube([25, 13, 7]);
+
+          // usb connector
+          // 10.32 wide, 0.73 to edge
+          cube([12, 22, 7]);
+
+          translate([25, 6.5, 8]) sphere(d=13);
+        }
+      }
+
+      // usb A-C converers
+      // 29 x 18 x 9
+      translate([innerWall + 38, innerWall - 0.5, 5])
+      for(i = [0,1]) {
+        translate([0, 28.5*2*i, 0])
+        mirror([0, i, 0])
+        union() {
+          // main body
+          cube([18, 29, 9]);
+
+          // release wedge
+          //color("blue")
+          translate([0, 28.5, -4])
+          rotate([-20, 0, 0])
+          translate([0, -29, 0])
+          cube([18, 29, 14]);
+        }
+      }
+    }
+  }
+}
 
 //audioLayer();
-translate([outerBoxWidth + 10, 0, 0]) audioTray1();
-//translate([outerBoxWidth + 10, 80, 0]) audioTray2();
-//translate([outerBoxWidth + 10, 160, 0]) audioTray3();
+//translate([outerBoxWidth + 10, 0, 0]) audioTray1();
+translate([outerBoxWidth + 10, 80, 0]) usbBitsTray();
+translate([outerBoxWidth + 10, 160, 0]) audioTray3();
+//translate([outerBoxWidth + 10, 240, 0]) audioTray2();