diff --git a/README.md b/README.md
index c374280..5d04e81 100644
--- a/README.md
+++ b/README.md
@@ -51,7 +51,14 @@ var_dump($response);
 $query =
     (new Query('/queue/simple/print'))
         ->where('target', '192.168.1.1/32');
+$request = $client->write($query);
 
+// Send advanced query with operations string
+$query =
+    (new Query('/interface/print'))
+        ->where('type', 'ether')
+        ->where('type', 'vlan')
+        ->operations('|');
 $request = $client->write($query);
 
 // Read answer from RouterOS
diff --git a/src/Query.php b/src/Query.php
index 5b2ccb8..ffe0d93 100644
--- a/src/Query.php
+++ b/src/Query.php
@@ -43,6 +43,16 @@ class Query implements QueryInterface
     private $_endpoint;
 
     /**
+     * List of available operators for "->where()" method
+     */
+    public const AVAILABLE_OPERATORS = [
+        '-',  // Does not have
+        '=',  // Equal
+        '>',  // More than
+        '<'   // Less than
+    ];
+
+    /**
      * Query constructor.
      *
      * @param array|string $endpoint   Path of endpoint
@@ -63,13 +73,6 @@ class Query implements QueryInterface
         }
     }
 
-    const AVAILABLE_OPERATORS = [
-        '-',  // Does not have
-        '=',  // Equal
-        '>',  // More than
-        '<'   // Less than
-    ];
-
     /**
      * Where logic of query
      *
@@ -77,7 +80,7 @@ class Query implements QueryInterface
      * @param bool|string|int $value    Value which need to check (by default true)
      * @param bool|string|int $operator It may be one from list [-,=,>,<]
      * @return \RouterOS\Query
-     * @throws \RouterOS\Exceptions\ClientException
+     * @throws \RouterOS\Exceptions\QueryException
      * @since 1.0.0
      */
     public function where(string $key, $operator = '=', $value = null): self
@@ -97,7 +100,7 @@ class Query implements QueryInterface
                 // Overwrite key
                 $key = $operator . $key;
             } else {
-                throw new ClientException('Operator "' . $operator . '" in not in allowed list [' . implode(',', self::AVAILABLE_OPERATORS) . ']');
+                throw new QueryException('Operator "' . $operator . '" in not in allowed list [' . implode(',', self::AVAILABLE_OPERATORS) . ']');
             }
         }
 
diff --git a/tests/QueryTest.php b/tests/QueryTest.php
index dd24ea4..26964c6 100644
--- a/tests/QueryTest.php
+++ b/tests/QueryTest.php
@@ -8,51 +8,51 @@ use RouterOS\Query;
 
 class QueryTest extends TestCase
 {
-    public function test__construct()
+    public function test__construct(): void
     {
         try {
             $obj = new Query('test');
-            $this->assertInternalType('object', $obj);
+            $this->assertIsObject($obj);
         } catch (\Exception $e) {
             $this->assertContains('Must be initialized ', $e->getMessage());
         }
     }
 
-    public function test__construct_arr()
+    public function test__construct_arr(): void
     {
         try {
             $obj = new Query('test', ['line1', 'line2', 'line3']);
-            $this->assertInternalType('object', $obj);
+            $this->assertIsObject($obj);
         } catch (\Exception $e) {
             $this->assertContains('Must be initialized ', $e->getMessage());
         }
     }
 
-    public function test__construct_arr2()
+    public function test__construct_arr2(): void
     {
         try {
             $obj = new Query(['test', 'line1', 'line2', 'line3']);
-            $this->assertInternalType('object', $obj);
+            $this->assertIsObject($obj);
         } catch (\Exception $e) {
             $this->assertContains('Must be initialized ', $e->getMessage());
         }
     }
 
-    public function testGetEndpoint()
+    public function testGetEndpoint(): void
     {
         $obj  = new Query('test');
         $test = $obj->getEndpoint();
         $this->assertEquals($test, 'test');
     }
 
-    public function testGetEndpoint2()
+    public function testGetEndpoint2(): void
     {
         $obj  = new Query(['zzz', 'line1', 'line2', 'line3']);
         $test = $obj->getEndpoint();
         $this->assertEquals($test, 'zzz');
     }
 
-    public function testGetEndpointEx()
+    public function testGetEndpointEx(): void
     {
         $this->expectException(QueryException::class);
 
@@ -60,7 +60,7 @@ class QueryTest extends TestCase
         $test = $obj->getEndpoint();
     }
 
-    public function testSetEndpoint()
+    public function testSetEndpoint(): void
     {
         $obj = new Query('test');
         $obj->setEndpoint('zzz');
@@ -68,14 +68,14 @@ class QueryTest extends TestCase
         $this->assertEquals($test, 'zzz');
     }
 
-    public function testGetAttributes()
+    public function testGetAttributes(): void
     {
         $obj  = new Query('test');
         $test = $obj->getAttributes();
         $this->assertCount(0, $test);
     }
 
-    public function testSetAttributes()
+    public function testSetAttributes(): void
     {
         $obj = new Query('test');
         $obj->setAttributes(['line1', 'line2', 'line3']);
@@ -83,7 +83,7 @@ class QueryTest extends TestCase
         $this->assertCount(3, $test);
     }
 
-    public function testAdd()
+    public function testAdd(): void
     {
         $obj = new Query('test');
         $obj->add('line');
@@ -93,7 +93,48 @@ class QueryTest extends TestCase
         $this->assertEquals($attrs[0], 'line');
     }
 
-    public function testGetQuery()
+    public function testWhere(): void
+    {
+        $obj = new Query('test');
+        $obj->where('key1', 'value1');
+        $obj->where('key2', 'value2');
+
+        $attrs = $obj->getAttributes();
+        $this->assertCount(2, $attrs);
+        $this->assertEquals($attrs[1], '?=key2=value2');
+    }
+
+    public function testTag(): void
+    {
+        $obj = new Query('/test/test');
+        $obj->where('key1', 'value1');
+        $obj->tag('test');
+
+        $query = $obj->getQuery();
+        $this->assertCount(3, $query);
+        $this->assertEquals($query[2], '.tag=test');
+    }
+
+    public function testOperator(): void
+    {
+        $obj = new Query('/test/test');
+        $obj->where('key1', 'value1');
+        $obj->operations('|');
+
+        $query = $obj->getQuery();
+        $this->assertCount(3, $query);
+        $this->assertEquals($query[2], '?#|');
+    }
+
+    public function testWhereEx(): void
+    {
+        $this->expectException(QueryException::class);
+
+        $obj = new Query('/richard/cheese');
+        $obj->where('people', 'equals', 'shit');
+    }
+
+    public function testGetQuery(): void
     {
         $obj = new Query('test');
         $obj->add('line');
@@ -104,7 +145,7 @@ class QueryTest extends TestCase
         $this->assertEquals($query[1], 'line');
     }
 
-    public function testGetQueryEx()
+    public function testGetQueryEx(): void
     {
         $this->expectException(QueryException::class);