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--- a/index.html
+++ b/index.html
@@ -165,7 +165,7 @@
 				<section>
 					<h3>Factory Tour!</h3>
 					<div>
-						<img src="img/xkcd-tasks.png" alt="It's hard to know when something is easy and when it's hard">
+						<img data-src="img/xkcd-tasks.png" alt="It's hard to know when something is easy and when it's hard">
 					</div>
 					<small>
 						<a href="https://xkcd.com/1425/">XKCD 1425</a>
@@ -373,7 +373,7 @@
 				</section>
 				<section>
 					<h3>3D Printing</h3>
-					<img src="img/3d-printed-cases.jpg" alt="3D case prototypes">
+					<img data-src="img/3d-printed-cases.jpg" alt="3D case prototypes">
 					<!-- <h3>Almost (but not quite) entirely unline injection molding</h3>
 					<ul>
 						<li>STL vs STEP</li>
@@ -391,6 +391,23 @@
 						they cut any steel.
 					</aside>
 				</section>
+				<section>
+					<h3>Reference</h3>
+					<img data-src="img/usb-schematics.png" alt="USB recepticle schematics">
+					<aside class="notes">
+						The USB specification is a five-megabyte PDF. Chapter 6 is the "Mechanical" chapter, and has lots of schematics
+						that are very important to this sort of project. This is a section of the "recepticle" schematic. It's important
+						to know the dimensions of where this connector will fit.
+					</aside>
+				</section>
+				<section>
+					<h3>Reference</h3>
+					<img data-src="img/usb-schematics-plug.png" alt="USB plug schematics">
+					<aside class="notes">
+						And this is a portion of the USB plug. Our goal is to have the case plus the PCB come out to roughly the same
+						shape as this plug, and still be able to fit into the recepticle. How do we do that, you ask?
+					</aside>
+				</section>
 				<section>
 					<h3>Hardware</h3>
 					<img data-src="img/tools-ruler-calipers.jpg" alt="Ruler and Caliper">
@@ -740,7 +757,7 @@
 				</section>
 				<section>
 					<h3>Manufactured!</h3>
-					<img src="img/manufactured.jpg" alt="Bag of Tomu cases">
+					<img data-src="img/manufactured.jpg" alt="Bag of Tomu cases">
 					<aside class="notes">
 						And then you have your final tool, ready to shoot thousands of copies of your model!
 					</aside>
@@ -806,7 +823,7 @@
 				</section>
 				<section>
 					<h3>Wine bottle opener</h3>
-					<img src="img/wine-bottle-overview.jpg" alt="Wine bottle bottle opener">
+					<img data-src="img/wine-bottle-overview.jpg" alt="Wine bottle bottle opener">
 					<aside class="notes">
 						This wine bottle opener has one very visible parting line. Interestingly, it's overmolded, which is where one
 						piece gets two shots, and the overmolded piece hides the parting line along the top.
@@ -814,7 +831,7 @@
 				</section>
 				<section>
 					<h3>Wine bottle opener</h3>
-					<img src="img/wind-bottle-flashing.jpg" alt="Some flashing on the wine bottle, plus overmolding">
+					<img data-src="img/wind-bottle-flashing.jpg" alt="Some flashing on the wine bottle, plus overmolding">
 					<aside class="notes">
 						You can do some pretty cool
 						thigns with overmolding, because the base doesn't even need to be plastic. You can overmold anything that will
@@ -830,6 +847,7 @@
 			<section>
 				<section>
 					<h2>Thank You</h2>
+					<h3>Questions?</h3>
 					<table>
 						<tr>
 							<td>Fomu:</td>