- Sourcing map ball roller with U-groove, designed for smooth and quiet sliding on sliding doors, windows, and mechanical equipment - Made of stainless steel and coated with nylon, offers high rust resistance and durability - Pack of 4 white wheels, each with dimensions of 6 x 26 x 8 mm (inner width x diameter x outer width) - Groove of 4 x 2.5 mm (width x depth), supports up to 41 kg load - Compatible with 1/5 inch round tube tracks - Easy installation, fits tracks or shafts of corresponding diameter - Ideal for industrial applications, furniture, and power transmission systems - Recommended to check periodically to ensure efficient operation and prolong service life