Universal Silent Sliding Plastic Door Roller Wheel Track Customized High-quality 50kg capacity sliding window roller featuring nylon plastic housing and 608ZZ carbon steel bearing. Designed for smooth, quiet operation in both residential and commercial sliding window and door applications. Key Specifications Attribute Value Material Nylon Plastic Housing with Carbon Steel Bearing Color Black Load Capacity 50kg Roller Diameter 25mm Track Thickness 2mm Installation Screw fixing