diff --git a/app/ModelFilters/DeviceFilter.php b/app/ModelFilters/DeviceFilter.php
index f371a1a..c825e11 100644
--- a/app/ModelFilters/DeviceFilter.php
+++ b/app/ModelFilters/DeviceFilter.php
@@ -6,6 +6,11 @@ use EloquentFilter\ModelFilter;
 
 class DeviceFilter extends ModelFilter
 {
+    public function sn($sn)
+    {
+        return $this->where('sn', $sn);
+    }
+
     public function point($point)
     {
         return $this->where('monitoring_point', 'like', $point.'%');