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 of durable plastic that can roll quietly and smoothly so as not to scratch 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 clearance according to the thickness of the door and tighten the screws to fix it. Easy DIY without tools. Wide use: The guide wheel is designed for 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. Note: The data are all measured manually, please allow 1-3cm error due to differences in light and display, there may be some color differences, please refer to the actual item received.