diff --git a/follow_focus.py b/follow_focus.py
index 532419c..5360a2d 100644
--- a/follow_focus.py
+++ b/follow_focus.py
@@ -114,7 +114,8 @@ lid = lid.faces('<Z[0]').workplane().circle(m_hole_diameter/2).cutBlind(-m_hole_
 # Threaded insert
 base = base.faces('<<Y[-1]').workplane().center(-5,0).circle(6.5/2).cutBlind(-t-mount_gap*2-6)
 base = base.faces('<<Y[-1]').workplane().circle(8.5/2).cutBlind(-t-mount_gap)
-# Hex mount point
+
+# Fastener
 fastener_width = 11
 fastener_height = 3.5
 fastener_length = 20
@@ -122,6 +123,8 @@ base = base.faces('<<Y[-1]').workplane().circle((fastener_width+1)/2).cutBlind(-
 fastener = base.faces('<<Y[-4]').workplane().circle(fastener_width/2).extrude(4.5+fastener_height, combine=False)
 fastener = fastener.faces('<<Y[-1]').workplane().center(-fastener_length,0).line(20,-fastener_width/2).vLine(fastener_width).close().extrude(-fastener_height)
 fastener = fastener.faces('<<Y[-1]').workplane().circle(fastener_width/6).extrude(-fastener_height)
+fastener = fastener.faces('<<Y[-1]').center(fastener_length,0).sketch().regularPolygon(8.5/2,6,tag='outer').finalize().cutBlind(-4)
+fastener = fastener.faces('<<Y[-6]').workplane().circle(5/2).cutThruAll()
 
 # Gears
 mod=0.8