diff --git a/include/Volumes/block.h b/include/Volumes/block.h
index c97232c..81a41dc 100644
--- a/include/Volumes/block.h
+++ b/include/Volumes/block.h
@@ -18,6 +18,14 @@
 #include <functional>
 
 namespace Volumes {
+    /*
+     *   4--5
+     *   | /
+     * 7-+6
+     *   3--2
+     *     /
+     * 0--1
+     * */
     class Block {
     public:
         explicit Block(LinAlg::Vector3 arr[8]) {