Anti-scratch and anti-rust to reduce noise: The bottom door guide track features a convenient galvanized cast iron seat and rubber pulley. The silver surface provides scratch resistance and rust protection, which can ensure long-term indoor or outdoor use. The rubber pulley is durable and can roll quietly and smoothly and reduce noise.100*31*40mm 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. No matter what size or type of automatic door 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 1.3" long top is installed on the left side of the door plate. guide at the bottom of the door, which can protect the door well and prevent the door from being damaged during movement. The specially designed sliding door kit, flat and rounded edges can protect the toes and knees from injury. Easy to install: The installation of automatic door accessories is very simple, just adjust the pulley to the position of the door panel, then tighten the screw at the bottom of the floor guide rail to fix the roller in the available position.The door does not need grooves, there are no holes in the floor, and installation does not take much time. Simple and practical appearance: the guide wheel is dedicated to automatic doors, sliding doors, framed doors, wooden doors and metal doors. The silver design fits most decoration styles, which is both beautiful and practical, and can match your door well. Meet all your needs, excellent quality will not let you down. Note: The data are manual measurement, please allow a 1-3cm error, due to the differences between the light and the display, there will be a certain color difference, the specific received in kind prevail.