diff --git a/Appendix-D:-Hardware.md b/Appendix-D:-Hardware.md
index f2160be..0b66c5c 100644
--- a/Appendix-D:-Hardware.md
+++ b/Appendix-D:-Hardware.md
@@ -21,7 +21,7 @@ First, a complete list of all the hardware you'll need:
 - 4x friction pads
 - 1x snooker ball
 
-We'll be going over all of them in detail. There will be mentions of *critical specifications*; if you're going to be sourcing your own parts, **you must get parts that conform to the critical specifications**. If you go off-menu, the parts will not fit the way that we intended when we designed the mouse. That might mean that your mouse **doesn't work**.
+We'll be going over all of them in detail. There will be mentions of *critical specifications*; if you're going to be sourcing your own parts, **you must get parts that conform to the critical specifications**. If you go off-menu, the parts will not fit the way that we intended when we designed the trackball. That might mean that your trackball **doesn't work**.
 
 Let's get cracking.