Sturdy and Durable: The silver surface provides scratch resistance and rust protection, which can ensure long-term use indoors or outdoors. The large roller wheel is made from durable plastic that can roll quietly and smoothly to keep from scratching your door. Suitable For: It can be installed on automatic doors with a thickness of 30mm to 60mm.The adjustable design makes it convenient and quick for you. Easy Installation: freely adjust the distance according to the thickness of the door and tighten the screws to fix it. Easy DIY without tools. Wide Use: The guide wheel is dedicated to automatic doors, sliding doors, frame doors, wooden doors, and metal doors. no need to punch holes in the wall, no damage. The design is very simple and beautiful.