diff --git a/upload/system/library/PagSeguro/src/Constants/AbstractEnum.php b/upload/system/library/PagSeguro/src/Constants/AbstractEnum.php
new file mode 100644
index 0000000..7f1f333
--- /dev/null
+++ b/upload/system/library/PagSeguro/src/Constants/AbstractEnum.php
@@ -0,0 +1,55 @@
+<?php
+
+namespace ValdeirPsr\PagSeguro\Constants;
+
+abstract class AbstractEnum
+{
+    private static $enums = [];
+
+    private function __construct()
+    {
+        /** Preventing instance */
+    }
+
+    /**
+     * Captura a lista de constantes
+     * 
+     * @return array
+     */
+    private static function getEnums(): array
+    {
+        if (self::$enums === null) {
+            self::$enums = [];
+        }
+
+        $calledClass = get_called_class();
+
+        if (!array_key_exists($calledClass, self::$enums)) {
+            $reflect = new \ReflectionClass($calledClass);
+            self::$enums[$calledClass] = $reflect->getConstants();
+        }
+
+        return self::$enums[$calledClass]; 
+    }
+
+    /**
+     * Verifica se determinada chave existe
+     * 
+     * @return bool
+     */
+    public static function has($name): bool
+    {
+        return array_key_exists($name, self::getEnums());
+    }
+
+    /**
+     * Verifica se determinado valor existe
+     * 
+     * @return bool
+     */
+    public static function isValidValue($value): bool
+    {
+        $values = array_values(self::getEnums());
+        return in_array($value, $values);
+    }
+}
diff --git a/upload/system/library/PagSeguro/src/Constants/Shipping/Type.php b/upload/system/library/PagSeguro/src/Constants/Shipping/Type.php
new file mode 100644
index 0000000..0d8fb5b
--- /dev/null
+++ b/upload/system/library/PagSeguro/src/Constants/Shipping/Type.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace ValdeirPsr\PagSeguro\Constants\Shipping;
+
+use ValdeirPsr\PagSeguro\Constants\AbstractEnum;
+
+class Type extends AbstractEnum
+{
+    const PAC = 1;
+    const SEDEX = 2;
+    const UNKNOWN = 3;
+}