Features: 1. Each product has a unique manufacturing part number label on the inner packaging, indicating 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-shaped groove plastic pulley with precise craftsmanship, lightweight design, smooth operation, and safe use. 4. The pulley bearing is made of POM polyacetal and bearing steel. Bearings are securely mounted, smooth to the touch, and operate quietly. 5. Higher-end pulleys allow height adjustment to compensate for the gap between the door and 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 applications such as sliding doors, windows, and furniture. Specifications: Material: Industrial Plastic Color: White Silver Name: BQLZR Max Load: 27 kg Size: 0.4 x 1.8 x 0.6 cm / 0.16 x 0.71 x 0.24 inch (D x L x W) Weight: 10 g Package Includes: 2 x U-Shaped Groove Plastic Pulley