diff --git a/assets/holder.FCStd b/assets/holder.FCStd
new file mode 100644
index 0000000..56b7d59
Binary files /dev/null and b/assets/holder.FCStd differ
diff --git a/parts.md b/parts.md
index 64edfb1..9b769cc 100644
--- a/parts.md
+++ b/parts.md
@@ -5,3 +5,6 @@
 [microUSB](https://www.aliexpress.com/item/32827910858.html)  
 [Jumper Wires](https://www.aliexpress.com/item/4000099476548.html)  
 
+# for 3d printing
+[Holder](assets/holder.FCStd)  
+