1. Stainless Steel and Copper Material: The sliding door roller assembly is made of premium stainless steel and copper, which is erosion resistance and wear proof, long service life. 2. Superior Workmanship: The bearing roller is manufactured to provide the performance and dependability you expect, ensures stable and lasting performance of doors and window. 3. Complete Accessories: The sliding door roller assembly set contains 4 rollers and 8 screws. Strong and practical, improve the efficiency of the doors. 4. Easy to Install: Remove damaged or missing wheel roller assemblies in patio sliding glass doors, then install the sliding door roller assembly. 5. Multiple Applications: The roller is suitable for most types of sliding doors and window. Improve the of your home or office by using reliable fittings.