diff --git a/src/common.scad b/src/common.scad
index a80f0e7..2f78271 100644
--- a/src/common.scad
+++ b/src/common.scad
@@ -9,5 +9,14 @@ module cubi(s, fillet=0, edges=EDGES_ALL) {
     }
 }
 
+module screwhole(d, h, head=true) {
+    $fn=$preview ? 5 : 20;
+    translate([0, 0, h]) cylinder(d=d*1.5, h=d*0.5);
+    split=h*0.5;
+    translate([0, 0, split]) cylinder(d=d, h=(h-split));
+    cylinder(d2=d, d1=d*0.1, h=split);
+    cylinder(d2=d*0.6, d1=d*0.6, h=split/2);
+}
+
 function vec_sum(v, w) = [v.x + w.x, v.y + w.y, v.z + w.z];
 
diff --git a/src/strap.scad b/src/strap.scad
index 6423e3c..4c02fd0 100644
--- a/src/strap.scad
+++ b/src/strap.scad
@@ -1,14 +1,22 @@
 links_count=3; // [1..20]
 include_terminal=true; // [true,false]
+include_screwhole=true; // [true,false]
+clip_screwhole=2;
+
+//export=302;//MODEL_CLIP_A;
+//export=303;//MODEL_CLIP_B;
 
 include <export.scad>
 use <BOSL/transforms.scad>
 use <BOSL/shapes.scad>
 include <BOSL/constants.scad>
 
+use <specs_strap.scad>
 use <specs_platform.scad>
 
+use <common.scad>
 use <strap_common.scad>
+use <platform_common.scad>
 
 if (is_model_strict(MODEL_LINKS)) {
     echo("===============================");
@@ -81,7 +89,13 @@ module clip() {
         slack=groove?0.2:0;
         joiner_size=[entry_size.x-6+slack, entry_size.y-6+slack, entry_size.z-3+slack];
         joiner_pos=[entry_pos.x, entry_pos.y, entry_pos.z - entry_size.z/2 + joiner_size.z/2];
-        translate(joiner_pos) cube(joiner_size, center=true);
+        difference() {
+            translate(joiner_pos) cube(joiner_size, center=true);
+            screw_cutout();
+        }
+    }
+    module screw_cutout() {
+        if (include_screwhole) down(clip_size.z/2) screwhole(d=clip_screwhole, h=clip_size.z);
     }
     
     module model() {
@@ -93,6 +107,7 @@ module clip() {
             }
             right(clip_size.x/2) socket_cutout();
             left(clip_size.x/2) socket_cutout();
+            screw_cutout();
         }
     }