diff --git a/app/Filament/Resources/PanelBoxValidationResource.php b/app/Filament/Resources/PanelBoxValidationResource.php
index ad3c4fa..05d5ed5 100644
--- a/app/Filament/Resources/PanelBoxValidationResource.php
+++ b/app/Filament/Resources/PanelBoxValidationResource.php
@@ -38,7 +38,7 @@ class PanelBoxValidationResource extends Resource
 {
     protected static ?string $model = PanelBoxValidation::class;
 
-    protected static ?string $navigationIcon = 'heroicon-o-rectangle-stack';
+    protected static ?string $navigationIcon = 'heroicon-o-clipboard-document-check';
 
     protected static ?string $navigationGroup = 'Panel Box';
 
@@ -581,6 +581,19 @@ class PanelBoxValidationResource extends Resource
                             $itemCode = $panelBoxCode;
                             $serialNumber = $panelBoxSerialNo;
 
+                            if (strlen($serialNumber) > 28) {
+                                Notification::make()
+                                    ->title('Invalid Serial Number')
+                                    ->body("Serial number cannot be greater than 28 characters. Current length: " . strlen($panelBoxSerialNo))
+                                    ->danger()
+                                    ->send();
+
+                                $set('item_id', null);
+                                $set('serial_exists', false);
+
+                                return;
+                            }
+
                             $existInMasterPo = PanelGrMaster::where('document_number', $pOrder)->where('plant_id', $plantId)->first();
 
                             if(!$existInMasterPo){