We have commodity security services. If the product you received has quality problems, please feel free to contact us, we can provide you with a return service.3M glue:1: Wipe the tile wall and make it dry and smooth.2: Lift the 3M tape and use it, and put the paper holder in the correct position.3: Stick the shelf to the wall and press firmly.4: Do not place anything on the shelf within 24 hours after installation. You can use it after 24 hours.Note:1. CAdhesives are suitable for smooth walls: wood, marble, metal, tiles, not for concrete walls, plaster walls.2. Due to manual measurement, please allow 1-3 cm difference, and seriously consider and take the actual product as the standard.3. If there is a quality problem, please contact us directly. We will provide you with a pleasant service within 24 hours.