Features: Name: Fixed rail wheels, plastic one-way small wheels Silent wheels: Smooth and silent, will not scratch ground Bearing capacity: 8KG when using 4 pulleys at the same time Easy to install: Just paste to the bottom of the storage box, suitcase, trash can, no need to move Size: 1.8 * 4.7 * 2.4cm Specification: Name: Fixed rail wheel 4pcs Material: ABS, POM, double-sided tape Include: Choice 1: 4pcs x Fixed rail wheels Choice 2: 8pcs x Fixed rail wheels Precaution: 1. This product is a one-way wheel 2. The adhesive of this product can not be removed, after leaving it will leave glue marks 3. Please use within the bearing range 4. This product may damage the floor surface, please use it with caution 5. After pasting this product to the bottom of the storage box, please leave it for 24 hours before use Package List: Choice 1: 4pcs x Fixed rail wheels Choice 2: 8pcs x Fixed rail wheels