When engaged door restrictors reduce the opening of the door enabling the occupant to identify and speak to the caller before the door is released and restrain against a forced attack. They are easier to operate and quieter than a standard door chain. Base Plate Size L x W mm 59 x 20 Corrosion Rating 2 - Occasionally damp/wet, rural and sheltered areas Description When engaged door restrictors reduce the opening of the door enabling the occupant to identify and speak to the caller before the door is released and restrain against a forced attack. They are easier to operate and quieter than a standard door chain. Finish Electro Brass Length mm 107 Material Zinc Alloy No. of CSK Screws 7 Product Code 200741 Screw Size imp. 6 x 1 Screw Size mm 3.5 x 25