Anti-scratch and anti-rust to reduce noise: The bottom door guide track has a practical galvanized cast iron seat and a rubber pulley. The silver surface provides scratch resistance and a rust protection, which can guarantee long-term use indoors or outdoors. The rubber pulley is durable and can roll quietly and smoothly and reduce noise. Adjustable Automatic Door Accessories: The rubber pulleys are adjustable to ensure a perfect fit. It can be installed on automatic doors with a thickness of 30 mm to 60 mm. Whatever the size or type of door automatic you have, it is applicable. We guarantee this automatic door accessory will provide a firm fit and can hold well. Provides more intimate protection: A 3.3cm long top is installed on the left side of the guide plate at the bottom of the door, which can protect the door well and prevent the door from being damaged during the movement. The door kit Specially designed slider, flat and rounded edges can protect toes and knees from injury.