diff --git a/Admin/Install/Media.install.json b/Admin/Install/Media.install.json
index e944548..31ef3e5 100755
--- a/Admin/Install/Media.install.json
+++ b/Admin/Install/Media.install.json
@@ -5,5 +5,24 @@
         "name": "Organization",
         "virtualPath": "/Modules",
         "user": 1
+    },
+    {
+        "type": "collection",
+        "create_directory": true,
+        "name": "Templates",
+        "virtualPath": "/Modules/Organization",
+        "user": 1
+    },
+    {
+        "type": "upload",
+        "create_collection": false,
+        "name": "Letter",
+        "type": "default_letter",
+        "virtualPath": "/Modules/Organization/Templates",
+        "path": "/Modules/Media/Files/Modules/Organization/Templates",
+        "files": [
+            "/Modules/Organization/Admin/Install/Media/letter.doc.php"
+        ],
+        "user": 1
     }
 ]
\ No newline at end of file
diff --git a/Admin/Install/Media/letter.doc.php b/Admin/Install/Media/letter.doc.php
new file mode 100644
index 0000000..e69de29
diff --git a/Admin/Install/db.json b/Admin/Install/db.json
index 710b826..196dfb8 100755
--- a/Admin/Install/db.json
+++ b/Admin/Install/db.json
@@ -51,6 +51,32 @@
             }
         }
     },
+    "organization_unit_media": {
+        "name": "organization_unit_media",
+        "fields": {
+            "organization_unit_media_id": {
+                "name": "organization_unit_media_id",
+                "type": "INT",
+                "null": false,
+                "primary": true,
+                "autoincrement": true
+            },
+            "organization_unit_media_src": {
+                "name": "organization_unit_media_src",
+                "type": "INT",
+                "null": false,
+                "foreignTable": "organization_unit",
+                "foreignKey": "organization_unit_id"
+            },
+            "organization_unit_media_dst": {
+                "name": "organization_unit_media_dst",
+                "type": "INT",
+                "null": false,
+                "foreignTable": "media",
+                "foreignKey": "media_id"
+            }
+        }
+    },
     "organization_department": {
         "name": "organization_department",
         "fields": {
diff --git a/Models/Unit.php b/Models/Unit.php
index d6fab4b..cfaff5b 100755
--- a/Models/Unit.php
+++ b/Models/Unit.php
@@ -84,6 +84,14 @@ class Unit implements \JsonSerializable, ArrayableInterface
      */
     protected int $status = Status::INACTIVE;
 
+    /**
+     * Media files
+     *
+     * @var array
+     * @since 1.0.0
+     */
+    protected array $files = [];
+
     /**
      * Constructor.
      *
@@ -107,6 +115,73 @@ class Unit implements \JsonSerializable, ArrayableInterface
         return $this->id;
     }
 
+    /**
+     * Get media.
+     *
+     * @return array
+     *
+     * @since 1.0.0
+     */
+    public function getFiles() : array
+    {
+        return $this->files;
+    }
+
+    /**
+     * Add media.
+     *
+     * @param Media $file Media
+     *
+     * @return void
+     *
+     * @since 1.0.0
+     */
+    public function addFile(Media $file) : void
+    {
+        $this->files[] = $file;
+    }
+
+    /**
+     * Get media file by type
+     *
+     * @param string $type Media type
+     *
+     * @return Media
+     *
+     * @since 1.0.0
+     */
+    public function getFileByType(string $type) : Media
+    {
+        foreach ($this->files as $file) {
+            if ($file->type === $type) {
+                return $file;
+            }
+        }
+
+        return new NullMedia();
+    }
+
+    /**
+     * Get all media files by type
+     *
+     * @param string $type Media type
+     *
+     * @return Media[]
+     *
+     * @since 1.0.0
+     */
+    public function getFilesByType(string $type) : array
+    {
+        $files = [];
+        foreach ($this->files as $file) {
+            if ($file->type === $type) {
+                $files[] = $file;
+            }
+        }
+
+        return $files;
+    }
+
     /**
      * Get status
      *
diff --git a/Models/UnitMapper.php b/Models/UnitMapper.php
index cd527fb..b610045 100755
--- a/Models/UnitMapper.php
+++ b/Models/UnitMapper.php
@@ -69,6 +69,21 @@ final class UnitMapper extends DataMapperAbstract
         ],
     ];
 
+    /**
+     * Has many relation.
+     *
+     * @var array<string, array{mapper:string, table:string, self?:?string, external?:?string, column?:string}>
+     * @since 1.0.0
+     */
+    protected static array $hasMany = [
+        'files'           => [
+            'mapper'   => MediaMapper::class,              /* mapper of the related object */
+            'table'    => 'organization_unit_media',       /* table of the related object, null if no relation table is used (many->1) */
+            'external' => 'organization_unit_media_dst',
+            'self'     => 'organization_unit_media_src',
+        ],
+    ];
+
     /**
      * Model to use by the mapper.
      *
diff --git a/Theme/Backend/Components/DepartmentTagSelector/department-selector.tpl.php b/Theme/Backend/Components/DepartmentTagSelector/department-selector.tpl.php
index fc52f4a..7f9e208 100755
--- a/Theme/Backend/Components/DepartmentTagSelector/department-selector.tpl.php
+++ b/Theme/Backend/Components/DepartmentTagSelector/department-selector.tpl.php
@@ -17,7 +17,7 @@
                     data-emptyAfter="true"
                     data-autocomplete="off"
                     data-src="api/organization/find/department?search={!#i<?= $this->getId(); ?>}">
-                <div id="<?= $this->getId(); ?>-dropdown" class="dropdown" data-active="true">
+                <div id="<?= $this->getId(); ?>-popup" class="popup" data-active="true">
                     <table class="default">
                         <thead>
                             <tr>
diff --git a/Theme/Backend/Components/PositionTagSelector/position-selector.tpl.php b/Theme/Backend/Components/PositionTagSelector/position-selector.tpl.php
index d9e341a..c10f04a 100755
--- a/Theme/Backend/Components/PositionTagSelector/position-selector.tpl.php
+++ b/Theme/Backend/Components/PositionTagSelector/position-selector.tpl.php
@@ -17,7 +17,7 @@
                     data-emptyAfter="true"
                     data-autocomplete="off"
                     data-src="api/organization/find/position?search={!#i<?= $this->getId(); ?>}">
-                <div id="<?= $this->getId(); ?>-dropdown" class="dropdown" data-active="true">
+                <div id="<?= $this->getId(); ?>-popup" class="popup" data-active="true">
                     <table class="default">
                         <thead>
                             <tr>
diff --git a/Theme/Backend/Components/UnitTagSelector/unit-selector.tpl.php b/Theme/Backend/Components/UnitTagSelector/unit-selector.tpl.php
index 5338537..ded1416 100755
--- a/Theme/Backend/Components/UnitTagSelector/unit-selector.tpl.php
+++ b/Theme/Backend/Components/UnitTagSelector/unit-selector.tpl.php
@@ -17,7 +17,7 @@
                     data-emptyAfter="true"
                     data-autocomplete="off"
                     data-src="api/organization/find/unit?search={!#i<?= $this->getId(); ?>}">
-                <div id="<?= $this->getId(); ?>-dropdown" class="dropdown" data-active="true">
+                <div id="<?= $this->getId(); ?>-popup" class="popup" data-active="true">
                     <table class="default">
                         <thead>
                             <tr>