diff --git a/delay_line.scad b/delay_line.scad
index c67bf74..87d21f5 100644
--- a/delay_line.scad
+++ b/delay_line.scad
@@ -47,11 +47,11 @@ info_block_offset_y=30;
 info_block_scale=0.3;
 title_text_size = 4;
 prop_text_size = 2.5;
-id_text_size = 2;
+id_text_size = 1;
 
 number_of_idts_per_quadrent=4;
 idt_x_spacing = 10;
-idt_y_spacing = 7;
+idt_y_spacing = 12.5;
 
 wafer_size_inch = 4;
 
@@ -185,16 +185,22 @@ module delay_line_idt(
     finger_length = 50, 
     gap = 0, 
     thickness = 0, 
-    impedance = 50, 
+    impedance = 50,
+
+    // bond pad prams
     has_bond_pads = false,
     bond_pad_leg_length = 0.00005, 
     bond_pad_leg_width = 0.00001875, 
     bond_pad_size = 0.000075,
     bond_pad_angle = 45,
     bond_pad_bond_pad_shape = "square",
-    post_scale = false,
+
+    // id number prams
     id_number = 0,
-    has_id = true
+    has_id = true,
+    id_flip_dir = [1, 1, 1],
+    // extra
+    post_scale = false
 ) {
 
     local_scale = 0;
@@ -207,7 +213,7 @@ module delay_line_idt(
         // n_fingers*lambda+lambda/2;
         
         
-        echo(str("lambda = ", lambda));
+        // echo(str("lambda = ", lambda));
         // echo(str("lambda/4 = ", lambda/4));
         // echo(str("lambda_scale = ", post_scale));
         delay_line(lambda, n_fingers, finger_length, gap, thickness);
@@ -215,8 +221,9 @@ module delay_line_idt(
 
 
         if (has_id) {
-            color([255/255, 0/255, 255/255]) 
+            color([255/255, 0/255, 255/255])
             translate([finger_length*lambda/2, has_bond_pads ? -(bond_pad_leg_length * post_scale * cos(bond_pad_angle)) : -lambda*finger_length/2, 0])
+            scale(id_flip_dir)
             text(str(id_number), size=id_text_size, halign="center");
         }
 
@@ -328,9 +335,9 @@ module wafer(d) {
 module prameter_text() {
 text(str("IDT ", substrate, "#", test_number), size=4, font=FONT);
 translate([0, -title_text_size, 0])    
-text(str("c              : ", c), size=prop_text_size, font=FONT);
+text(str("c          (ms): ", c), size=prop_text_size, font=FONT);
 translate([0, -title_text_size*2, 0])    
-text(str("freq           : ", freq), size=prop_text_size, font=FONT);
+text(str("freq       (Hz): ", freq), size=prop_text_size, font=FONT);
 translate([0, -title_text_size*3, 0])    
 text(str("distance       : ", distance), size=prop_text_size, font=FONT);
 translate([0, -title_text_size*4, 0])    
@@ -387,11 +394,11 @@ scale([info_block_scale, info_block_scale, info_block_scale]) {
 //     bond_pad_size = size 
 // );
 
-
-// wafer(wafer_size_inch*25.4);
+if ($preview)
+wafer(wafer_size_inch*25.4*post_scale);
 for (i=[0:number_of_idts_per_quadrent-1]) {
     translate([idt_x_spacing/4, 0, 0]) {
-    translate([i * idt_x_spacing, idt_y_spacing, 0]) {
+    translate([i * idt_x_spacing, idt_y_spacing/2, 0]) {
             delay_line_idt(
                 c, 
                 freq, 
@@ -405,10 +412,11 @@ for (i=[0:number_of_idts_per_quadrent-1]) {
                 bond_pad_angle = leg_angle,
                 bond_pad_leg_width = leg_width,
                 bond_pad_leg_length = leg_length,
-                bond_pad_size = size 
+                bond_pad_size = size,
+                id_number = i
             );
     }
-    translate([i * idt_x_spacing, -idt_y_spacing, 0]) {
+    translate([i * idt_x_spacing, -idt_y_spacing/2, 0]) {
         scale([1, -1, 1]) {
             delay_line_idt(
                 c, 
@@ -423,16 +431,18 @@ for (i=[0:number_of_idts_per_quadrent-1]) {
                 bond_pad_angle = leg_angle,
                 bond_pad_leg_width = leg_width,
                 bond_pad_leg_length = leg_length,
-                bond_pad_size = size 
+                bond_pad_size = size,
+                id_number = i + number_of_idts_per_quadrent,
+                id_flip_dir = [1, -1, -1]
             );
-        }
+       }
     }
     }
 
     scale([-1, 1, 1])
     translate([idt_x_spacing/4, 0, 0]) {
         
-    translate([i * idt_x_spacing, idt_y_spacing, 0]) {
+    translate([i * idt_x_spacing, idt_y_spacing/2, 0]) {
             delay_line_idt(
                 c, 
                 freq, 
@@ -446,10 +456,12 @@ for (i=[0:number_of_idts_per_quadrent-1]) {
                 bond_pad_angle = leg_angle,
                 bond_pad_leg_width = leg_width,
                 bond_pad_leg_length = leg_length,
-                bond_pad_size = size 
+                bond_pad_size = size, 
+                id_number = i + number_of_idts_per_quadrent*2,
+                id_flip_dir = [-1, 1, 1]
             );
     }
-    translate([i * idt_x_spacing, -idt_y_spacing, 0]) {
+    translate([i * idt_x_spacing, -idt_y_spacing/2, 0]) {
         scale([1, -1, 1]) {
             delay_line_idt(
                 c, 
@@ -464,7 +476,9 @@ for (i=[0:number_of_idts_per_quadrent-1]) {
                 bond_pad_angle = leg_angle,
                 bond_pad_leg_width = leg_width,
                 bond_pad_leg_length = leg_length,
-                bond_pad_size = size 
+                bond_pad_size = size, 
+                id_number = i + number_of_idts_per_quadrent*3,
+                id_flip_dir = [-1, -1, 1]
             );
         }
     }