General description Upgraded office chair casters designed for high performance and durability. These heavy-duty casters support up to 250 kg, featuring a wide and thick double-wheel structure made from soft PU material that is pressure-resistant, quiet, and smooth. They will not scratch or leave marks on floors. Technical specifications Material: Steel and TPR rubber Wheel Diameter: 50mm Width: 20mm Mounting Height: 57mm Universal Fit: Stem Size: 11mm x 22mm (not compatible with IKEA chairs which have a 10mm x 22mm stem) Maximum Load: 250 kg Color: Black Installation Easy to install without tools or hardware Simply remove the old casters and slide the new ones into place Usage Provides a stylish and comfortable upgrade for office chairs or regular chairs Dual-wheel design improves weight distribution and smooth operation Soft rubber surface prevents damage to natural and wooden floors Leaves no marks on tile floors, special floors, and smooth concrete/asphalt floors