diff --git a/shopping-carts/7.8khz-audio-files/lock-cart.wav b/shopping-carts/7.8khz-audio-files/lock-cart.wav
new file mode 100644
index 00000000..2b3c5b73
Binary files /dev/null and b/shopping-carts/7.8khz-audio-files/lock-cart.wav differ
diff --git a/shopping-carts/7.8khz-audio-files/unlock-cart.wav b/shopping-carts/7.8khz-audio-files/unlock-cart.wav
new file mode 100644
index 00000000..66cf4eab
Binary files /dev/null and b/shopping-carts/7.8khz-audio-files/unlock-cart.wav differ
diff --git a/shopping-carts/Readme.md b/shopping-carts/Readme.md
new file mode 100644
index 00000000..c53fa7ea
--- /dev/null
+++ b/shopping-carts/Readme.md
@@ -0,0 +1,8 @@
+# Shopping cart wheel unlock/lock files
+
+Credits to jdmoore#4658 for modifying the files to work on the FZ<br>
+Original files from: https://www.begaydocrime.com/#
+
+## How it works
+
+Most electronic shopping cart wheels listen for a 7.8 kHz signal from an underground wire to know when to lock and unlock. A management remote can send a different signal at 7.8 kHz to the wheel to unlock it. Since 7.8 kHz is in the audio range, you can use the parasitic EMF from your phone's speaker to "transmit" a similar code by playing a crafted audio file.