diff --git a/model/MongoModel.php b/model/MongoModel.php
index 91f2bf7..f26c582 100644
--- a/model/MongoModel.php
+++ b/model/MongoModel.php
@@ -13,23 +13,40 @@
 abstract class MongoModel extends Model
 {
 
+    protected $useMongoId = true;
+
+    public function __construct($connection = 'default')
+    {
+        parent::__construct($connection);
+    }
+
     public function count($query = array(), $limit = 0, $skip = 0)
     {
         return $this->db->count($this->table(), $query, $limit, $skip);
     }
 
-    public function find($condition = array())
+    public function find($condition = array(), $fields = array())
     {
-        return $this->db->find($this->table(), $condition);
+        return $this->db->find($this->table(), $condition, $fields);
     }
 
     public function get($id)
     {
+        if($this->useMongoId) {
+            if(! $id instanceof MongoId) {
+                $id = new MongoId($id);
+            }
+        }
         return $this->db->get($this->table(), array('_id' => $id))->fetch();
     }
 
     public function delete($id)
     {
+        if($this->useMongoId) {
+            if(! $id instanceof MongoId) {
+                $id = new MongoId($id);
+            }
+        }
         return $this->db->delete($this->table(), array('_id' => $id));
     }
 
diff --git a/tests/model/MongoModelTest.php b/tests/model/MongoModelTest.php
index c9cc58c..1a37774 100644
--- a/tests/model/MongoModelTest.php
+++ b/tests/model/MongoModelTest.php
@@ -40,7 +40,7 @@ class MongoModelTest extends PHPUnit_Framework_TestCase
         $conf = array('default' => array('driver' => 'MongoDriver', 'hostname' => 'localhost', 'database' => 'test', 'username' => 'test', 'password' => '1234', 'port' => 27017));
 
         $this->dbSetUp($conf);
-        
+
         Config::set('Db', $conf);
         if (!class_exists('MockModel')) {
             $this->model = $this->getMockForAbstractClass('MongoModel', array(), 'MongoMockModel');
@@ -71,6 +71,10 @@ class MongoModelTest extends PHPUnit_Framework_TestCase
         $this->assertInstanceOf('MongoStatement', $result);
         $this->assertEquals('milk', $result->limit(2)->order(array('name' => -1))->fetch()->name);
         $this->assertEquals('fish', $result->fetch()->name);
+        $result = $this->model->find(array(), array('name'))->fetch();
+        $this->assertSame('bread', $result->name);
+        $this->setExpectedException('PHPUnit_Framework_Error');
+        $this->assertNull($result->price);
     }
 
     /**
@@ -144,11 +148,11 @@ class MongoModelTest extends PHPUnit_Framework_TestCase
 
         $mock = $this->getMock('CacheKey', array('set', 'get'));
         $mock->expects($this->exactly(3))
-            ->method('set')
-            ->will($this->returnValue(true));
+                ->method('set')
+                ->will($this->returnValue(true));
         $mock->expects($this->exactly(3))
-            ->method('get')
-            ->will($this->returnValue(false));
+                ->method('get')
+                ->will($this->returnValue(false));
 
         $model = new ReflectionClass('MongoModel');
         $method = $model->getMethod('fetchField');
@@ -173,11 +177,66 @@ class MongoModelTest extends PHPUnit_Framework_TestCase
         $this->assertEquals('eggs', $result[0]->name);
     }
 
+    /**
+     * @runInSeparateProcess
+     * @group Mongo
+     */
+    public function testUseMongoId()
+    {
+        if (!defined('DEBUG')) {
+            define('DEBUG', false);
+        }
+
+        $this->assertAttributeEquals(true, 'useMongoId', $this->model);
+    }
+
+    /**
+     * @runInSeparateProcess
+     * @group Mongo
+     */
+    public function testId()
+    {
+        if (!defined('DEBUG')) {
+            define('DEBUG', false);
+        }
+        $class = new ReflectionClass('MongoModel');
+        $prop = $class->getProperty('useMongoId');
+        $prop->setAccessible(true);
+
+        $this->model->insert(array('_id' => 1, 'name' => 'testbread', 'price' => 3.2, 'quantity' => 10));
+        $this->model->insert(array('_id' => 2, 'name' => 'testbread', 'price' => 12, 'quantity' => 2));
+        $this->assertSame(2, $this->model->count(array('name' => 'testbread')));
+        
+        $prop->setValue($this->model, false);
+        $this->model->delete(1);
+        $this->assertSame(1, $this->model->count(array('name' => 'testbread')));
+    }
+
+    /**
+     * @runInSeparateProcess
+     * @group Mongo
+     */
+    public function testIdToMongoId()
+    {
+        if (!defined('DEBUG')) {
+            define('DEBUG', false);
+        }
+
+        $this->model->insert(array('name' => 'testbread', 'price' => 3.2, 'quantity' => 10));
+        $this->model->insert(array('name' => 'testbread', 'price' => 12, 'quantity' => 2));
+        $this->assertSame(2, $this->model->count(array('name' => 'testbread')));
+        $id = $this->model->find(array('name' => 'testbread'))->limit(1)->fetch()->_id->__toString();
+        $this->assertInternalType('string', $id);
+        $item = $this->model->get($id);
+        $this->assertSame('testbread', $item->name);
+        $this->model->delete($id);
+        $this->assertSame(1, $this->model->count(array('name' => 'testbread')));
+    }
+
     public function tearDown()
     {
         $conf = array('driver' => 'MongoDriver', 'hostname' => 'localhost', 'database' => 'test', 'username' => 'test', 'password' => '1234', 'port' => 27017);
 
-
         $connection = new Mongo('mongodb://' . $conf['hostname'] . ':' . $conf['port']);
         $db = $connection->selectDB($conf['database']);
         $db->authenticate($conf['username'], $conf['password']);
@@ -230,9 +289,8 @@ class MongoModelTest extends PHPUnit_Framework_TestCase
         $collection = 'mongomock';
         $db->dropCollection($collection);
         $collection = $db->selectCollection($collection);
-        foreach($data as $document) {
+        foreach ($data as $document) {
             $collection->insert($document);
         }
     }
-
 }