diff --git a/scad/YOOPAI_round_to_rectangular_duct_transition_adapter.scad b/scad/YOOPAI_round_to_rectangular_duct_transition_adapter.scad
deleted file mode 100644
index 26cc9e8..0000000
--- a/scad/YOOPAI_round_to_rectangular_duct_transition_adapter.scad
+++ /dev/null
@@ -1,197 +0,0 @@
-//
-// duct_round_to_window_slot.scad
-// 20260321 ChatGPT
-// $Id$
-// $HeadURL$
-//
-// Example command lines:
-//
-//   openscad -o duct_round_to_window_slot_20260321_1830.stl duct_round_to_window_slot.scad
-//
-//   openscad \
-//     -D 'round_stub_od=72.0' \
-//     -D 'round_fit_clearance=0.6' \
-//     -D 'slot_h=25.4' \
-//     -D 'slot_w=162.0' \
-//     -D 'wall=2.4' \
-//     -D 'round_stub_len=30' \
-//     -D 'transition_len=140' \
-//     -D 'slot_stub_len=30' \
-//     -o duct_round_to_window_slot_20260321_1831.stl \
-//     duct_round_to_window_slot.scad
-//
-
-$fn = 128;
-
-// ------------------------------------------------------------
-// PARAMETERS
-// ------------------------------------------------------------
-
-// Measured OD of the existing plastic tent outlet that your flex duct
-// currently wraps around.
-round_stub_od = 72.0;
-
-// Extra diameter added so the flex duct can slip over this printed stub.
-// Start with 0.4 to 0.8 mm and adjust after a test print.
-round_fit_clearance = 0.6;
-
-// Wall thickness
-wall = 2.4;
-
-// Length of straight circular collar for flex duct attachment
-round_stub_len = 30;
-
-// Length of tapered transition body
-transition_len = 140;
-
-// Length of straight rectangular outlet section for insertion under window
-slot_stub_len = 30;
-
-// Window slot internal size
-slot_h = 25.4;      // 1.0 inch
-slot_w = 162.0;     // approximately area-preserving for 72 mm round
-
-// Corner radius for rounded rectangle, internal passage
-slot_r = 6.0;
-
-// Optional lip / stop ring on circular end so the duct has something
-// to register against before clamp/strap tightening.
-add_round_stop_ring = true;
-round_stop_ring_len = 5.0;
-round_stop_ring_extra_od = 6.0;
-
-
-// ------------------------------------------------------------
-// DERIVED VALUES
-// ------------------------------------------------------------
-
-// This is the OD of the printed round collar that the flexible duct
-// will fit around.
-round_outer_d = round_stub_od + round_fit_clearance;
-
-// Inner flow diameter at the round side
-round_inner_d = round_outer_d - 2*wall;
-
-// Outer dimensions of the rectangular outlet
-slot_outer_h = slot_h + 2*wall;
-slot_outer_w = slot_w + 2*wall;
-slot_outer_r = slot_r + wall;
-
-// Z locations
-z0 = 0;
-z1 = round_stub_len;
-z2 = round_stub_len + transition_len;
-z3 = round_stub_len + transition_len + slot_stub_len;
-
-
-// ------------------------------------------------------------
-// HELPERS
-// ------------------------------------------------------------
-
-module rounded_rect_2d(w, h, r) {
-    rr = min(r, min(w,h)/2 - 0.01);
-    hull() {
-        translate([-(w/2 - rr), -(h/2 - rr)]) circle(r=rr);
-        translate([ +(w/2 - rr), -(h/2 - rr)]) circle(r=rr);
-        translate([-(w/2 - rr), +(h/2 - rr)]) circle(r=rr);
-        translate([ +(w/2 - rr), +(h/2 - rr)]) circle(r=rr);
-    }
-}
-
-module round_profile_3d(d, z, h=1) {
-    translate([0,0,z])
-        linear_extrude(height=h)
-            circle(d=d);
-}
-
-module rect_profile_3d(w, h_rect, r, z, h=1) {
-    translate([0,0,z])
-        linear_extrude(height=h)
-            rounded_rect_2d(w, h_rect, r);
-}
-
-
-// ------------------------------------------------------------
-// OUTER SHELL
-// ------------------------------------------------------------
-
-module outer_shell() {
-    union() {
-        // Straight round collar
-        hull() {
-            round_profile_3d(round_outer_d, z0, 1);
-            round_profile_3d(round_outer_d, z1, 1);
-        }
-
-        // Transition
-        hull() {
-            round_profile_3d(round_outer_d, z1, 1);
-            rect_profile_3d(slot_outer_w, slot_outer_h, slot_outer_r, z2, 1);
-        }
-
-        // Straight rectangular collar
-        hull() {
-            rect_profile_3d(slot_outer_w, slot_outer_h, slot_outer_r, z2, 1);
-            rect_profile_3d(slot_outer_w, slot_outer_h, slot_outer_r, z3, 1);
-        }
-    }
-}
-
-
-// ------------------------------------------------------------
-// INNER VOID
-// ------------------------------------------------------------
-
-module inner_void() {
-    union() {
-        // Straight round passage
-        hull() {
-            round_profile_3d(round_inner_d, z0 - 0.2, 1.4);
-            round_profile_3d(round_inner_d, z1 + 0.2, 1.4);
-        }
-
-        // Transition passage
-        hull() {
-            round_profile_3d(round_inner_d, z1 - 0.2, 1.4);
-            rect_profile_3d(slot_w, slot_h, slot_r, z2 + 0.2, 1.4);
-        }
-
-        // Straight rectangular passage
-        hull() {
-            rect_profile_3d(slot_w, slot_h, slot_r, z2 - 0.2, 1.4);
-            rect_profile_3d(slot_w, slot_h, slot_r, z3 + 0.2, 1.4);
-        }
-    }
-}
-
-
-// ------------------------------------------------------------
-// OPTIONAL ROUND STOP RING
-// ------------------------------------------------------------
-
-module round_stop_ring() {
-    if (add_round_stop_ring) {
-        translate([0,0,z0]) {
-            difference() {
-                cylinder(d = round_outer_d + round_stop_ring_extra_od,
-                         h = round_stop_ring_len);
-                translate([0,0,-0.2])
-                    cylinder(d = round_outer_d,
-                             h = round_stop_ring_len + 0.4);
-            }
-        }
-    }
-}
-
-
-// ------------------------------------------------------------
-// FINAL PART
-// ------------------------------------------------------------
-
-union() {
-    difference() {
-        outer_shell();
-        inner_void();
-    }
-    round_stop_ring();
-}