diff --git a/src/main/java/cc/carm/plugin/userprefix/conf/prefix/PrefixConfig.java b/src/main/java/cc/carm/plugin/userprefix/conf/prefix/PrefixConfig.java
index 45c557b..f55da23 100644
--- a/src/main/java/cc/carm/plugin/userprefix/conf/prefix/PrefixConfig.java
+++ b/src/main/java/cc/carm/plugin/userprefix/conf/prefix/PrefixConfig.java
@@ -87,7 +87,6 @@ public class PrefixConfig {
 
     @Contract("_,!null->!null")
     protected @Nullable ItemStack getItem(@Nullable Player player, @Nullable ItemStack item) {
-        if (item == null) return null;
         return PreparedItem.of(item).get(player);
     }
 
diff --git a/src/main/java/cc/carm/plugin/userprefix/ui/PrefixSelectGUI.java b/src/main/java/cc/carm/plugin/userprefix/ui/PrefixSelectGUI.java
index c2606a4..9e643b0 100644
--- a/src/main/java/cc/carm/plugin/userprefix/ui/PrefixSelectGUI.java
+++ b/src/main/java/cc/carm/plugin/userprefix/ui/PrefixSelectGUI.java
@@ -14,6 +14,7 @@ import org.bukkit.event.inventory.ClickType;
 import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
+import java.util.Optional;
 
 public class PrefixSelectGUI extends AutoPagedGUI {
 
@@ -49,7 +50,10 @@ public class PrefixSelectGUI extends AutoPagedGUI {
 
         for (PrefixConfig prefix : prefixList) {
             if (prefix.getIdentifier().equals(usingPrefix.getIdentifier())) {
-                addItem(new GUIItem(prefix.getItemWhenUsing(player) != null ? prefix.getItemWhenUsing(player) : prefix.getItemHasPermission(player)));
+                addItem(new GUIItem(Optional
+                        .ofNullable(prefix.getItemWhenUsing(player))
+                        .orElse(prefix.getItemHasPermission(player))
+                ));
             } else if (prefix.checkPermission(player)) {
                 addItem(new GUIItem(prefix.getItemHasPermission(player)) {
 
diff --git a/src/main/resources/ejemplo-prefijo.yml b/src/main/resources/ejemplo-prefijo.yml
index e36ed2c..5d77ab9 100644
--- a/src/main/resources/ejemplo-prefijo.yml
+++ b/src/main/resources/ejemplo-prefijo.yml
@@ -28,7 +28,7 @@ item:
   # itemHasPermission  [Necesario]
   # Este elemento se mostrará cuando el jugador tenga permiso
   has-perm:
-    type: DIAMOND
+    material: DIAMOND
     name: "&b&lVIP Prefix"
     lore:
       - ""
@@ -38,7 +38,7 @@ item:
   # Este elemento se mostrará cuando se seleccione el prefijo.
   # Si no existe tal configuración, se mostrará automáticamente "itemHasPermission".
   using:
-    type: DIAMOND
+    material: DIAMOND
     name: "&b&lVIP Prefix"
     enchants:
       PROTECTION_ENVIRONMENTAL: 1 #Añade un encantamiento para que parezca que está seleccionado
@@ -50,7 +50,7 @@ item:
   # Si el jugador no tiene el permiso,este item sera mostrado.
   # Si este elemento no está configurado, no se mostrará en la GUI cuando el jugador no tenga permiso para usarlo.
   no-perm:
-    type: INK_SACK
+    material: INK_SACK
     data: 8
     name: "&b&lVIP &c(¡Cómpralo!)"
     lore:
diff --git a/src/main/resources/en_US/example-prefix.yml b/src/main/resources/en_US/example-prefix.yml
index b148183..942f5f8 100644
--- a/src/main/resources/en_US/example-prefix.yml
+++ b/src/main/resources/en_US/example-prefix.yml
@@ -31,7 +31,7 @@ item:
   # itemHasPermission  [Necessary]
   # This Item will be displayed when player has permission
   has-perm:
-    type: DIAMOND
+    material: DIAMOND
     name: "&b&lVIP Prefix"
     lore:
       - ""
@@ -41,7 +41,7 @@ item:
   # This Item will be displayed when the prefix is selected.
   # If there is no such configuration, it will automatically display "itemHasPermission".
   using:
-    type: DIAMOND
+    material: DIAMOND
     name: "&b&lVIP Prefix"
     enchants:
       PROTECTION_ENVIRONMENTAL: 1 #Add an enchantment so it looks like it’s selected
@@ -53,7 +53,7 @@ item:
   # If player doesn't have the permission,this item will be displayed.
   # If this item is not configured, it will not be displayed in the GUI when the player does not have permission to use it.
   no-perm:
-    type: INK_SACK
+    material: INK_SACK
     data: 8
     name: "&b&lVIP &c(Buy it!)"
     lore:
diff --git a/src/main/resources/prefixes/example-prefix.yml b/src/main/resources/prefixes/example-prefix.yml
index b36f834..d6e2ce5 100644
--- a/src/main/resources/prefixes/example-prefix.yml
+++ b/src/main/resources/prefixes/example-prefix.yml
@@ -35,7 +35,7 @@ item:
   # 有权限时显示的物品  [必须]
   # 当用户有权限且未选中时，会显示该物品
   has-perm:
-    type: DIAMOND
+    material: DIAMOND
     name: "&b&lPro &b会员前缀"
     lore:
       - "&7Pro会员专属称号"
@@ -48,7 +48,7 @@ item:
   # 正在使用时显示的物品 [非必需]
   # 当用户正在使用时会显示这个物品，不配置即自动加载“itemHasPermission”
   using:
-    type: DIAMOND
+    material: DIAMOND
     name: "&b&lPro &b会员前缀"
     flags:
       - HIDE_ENCHANTS # 隐藏附魔显示
@@ -65,7 +65,7 @@ item:
   # 没有权限时显示的物品 [非必需]
   # 如果没有权限就会显示这个item。如果不配置该物品，则玩家没有使用权限时不会显示在GUI里面。
   no-perm:
-    type: INK_SACK
+    material: INK_SACK
     data: 8
     name: "&b&lPro+ &b会员前缀 &c(未拥有)"
     lore: