The middle door pulley bracket is made of metal, which is stable and durable; the roller part is made of high-strength engineering plastic, which has good wear resistance and stability. Features: Our sliding door rollers maintain smooth operation, ensuring easier and less effort to open and close, thus improving the reliability and functionality of sliding doors; Material: These sliding door rollers are made of metal using high-precision machining and assembly processes; Easy Installation: This door hinge is designed for easy installation, conforms to standard specifications, and is quick and simple to replace; It helps to alleviate the jamming, abnormal noise or shaking of the sliding door during use and improve the operation of the door body., Manufacturer: PENGNAQP