Features: 1. Every product has a unique Manufacturing Part Number label on the inner package that proves it has been qualified, including Part Number, Model Number, and inspection date information. 2. If you have any questions about the item, please provide the Manufacturing Part Number for verification. 3. This product is a U-shape groove plastic pulley with excellent workmanship and fine craftsmanship. It is lightweight, easy to pull, and safe to use. 4. The pulley bearing is made of POM polyacetal and bearing steel. The bearings are securely mounted, smooth to the touch, and operate quietly. 5. Higher-end pulleys can adjust the height to compensate for the distance between the door and the track, ensuring a closer connection between the door and track. 6. High-quality pulleys significantly enhance the performance of doors and windows. The pulley is an essential component in sliding hardware, such as sliding doors, windows, and furniture. Specifications: Material: Industrial Plastic Color: White Silver Name: BQLZR Max-load: 27kg Size: 0.4x1.8x0.6cm / 0.16x0.71x0.24inch (dxDxW) Weight: 10g Package Includes: 2 x U-shape Groove Plastic Pulley