These sliding gates have been best sellers for over 40 years ago. They have a robust double trellis design that opens and closes smoothly and easily. Trellidor customers can choose between steel or aluminium sliding gates. There is a choice of either the Trellidor patented deadlock or slamlock. These expanding gates can be custom-made to fit doors, windows, passages, patios, hatches and most other building openings, keeping them safe from intrusion.