Description Description: Made of high-quality plastic, smooth sliding, strong load- bearing,durability and high shock absorption. These casters allow you to roll smoothly and quietly without making harsh noises, and ensure that you dont scratch or leave marks on any surface. Adhesive design, installed on the bottom box, no need tools. The rotation of the casters and the precision ball bearings makes smooth and quiet movement. The wheels are suitable for different types of storage box, small cabinet, garbage trush box, tissue box, etc, making it easier to move. Specification: Material: Plastic Size:4.5x2cm/1.77x0.79inch Package Includes: 8 Pieces Storage Box Roller : Please allow slight dimension difference due to different manual measurement.