ComboBox Model Java

When i Populate combo box with array list .. Strange elements appears this

i added in jCombo Box >> properties >> model >> custom code (this next line)

new DefaultComboBoxModel(arr.toArray())

and here is the code in gui which i declared my arraylist

public class adminsystem extends javax.swing.JFrame {
Apparels app = new Apparels();
public static ArrayList<Apparels> arr= new ArrayList<Apparels>();

DefaultComboBoxModel cateogry;

public adminsystem() {

    this.cateogry= new DefaultComboBoxModel();
    arr=app.listCateogry();
    initComponents();
}

so i want to fill the combo box with the array list elements( which i load from bin file )
and passes it to my arraylist