diff --git a/hardware/jawbreaker/README b/hardware/jawbreaker/README
index 52906625..47f3fe3b 100644
--- a/hardware/jawbreaker/README
+++ b/hardware/jawbreaker/README
@@ -27,20 +27,20 @@ Schematic and layout files were designed in KiCad, an open source electronic
 design automation package.
 
 order of copper layers:
-    Front
-    Inner3
-    Inner2
-    Back
+    Copper 1: Front
+    Copper 2: Inner3
+    Copper 3: Inner2
+    Copper 4: Back
 
-PCB description: 4 layer PCB 1.6 mm
-    Copper        1   35 um
-    Dielectric  1-2   0.35 mm
-    Copper        2   18 um
-    Dielectric  2-3   0.76 mm
-    Copper        3   18 um
-    Dielectric  3-4   0.35 mm
-    Copper        4   35 um
-DE104iML or equivalent substrate (Er=4.42@2.4GHz TanD=0.016)
+PCB description: 4 layer PCB 0.062 in
+    Copper        1   0.5 oz foil plated to approximately 0.0017 in
+    Dielectric  1-2   0.0119 in
+    Copper        2   1 oz foil (0.0014 in)
+    Dielectric  2-3   0.0280 in
+    Copper        3   1 oz foil (0.0014 in)
+    Dielectric  3-4   0.0119 in
+    Copper        4   0.5 oz foil plated to approximately 0.0017 in
+FR4 or similar substrate with Er=4.5 (+/- 0.1)
 double side solder mask black
 double side silkscreen white
 6 mil min trace width and