diff --git a/README.md b/README.md
index 6cbb5c8..a3e3e24 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,7 @@ Custom interface classes with instantiate, initialize, listen, load functions. W
 
 - Activity
 - BundleBuilder
+- Callback
 - DialogFragment
 - Fragment
 - JSONBuilder
diff --git a/custom/src/main/java/com/isolpro/custom/Callback.java b/custom/src/main/java/com/isolpro/custom/Callback.java
new file mode 100755
index 0000000..40e3f49
--- /dev/null
+++ b/custom/src/main/java/com/isolpro/custom/Callback.java
@@ -0,0 +1,5 @@
+package com.isolpro.custom;
+
+public interface Callback<T> {
+  void exec(T object);
+}