SMOOTH AND SILENT MOVEMENT - Custom-designed dual-wheel construction with four high-precise bearings and, soft polyurethane casters ensure your office chair glides quietly and smoothly across all surfaces. Perfect for maintaining focus in work, leisure, or gaming environments, whether at home or in the office SUPERIOR FLOOR PROTECTION - Made from high-quality soft polyurethane, casters prevent scratches and negate the need for chair mats. They glide smoothly across all types of flooring, including hardwood, laminate, vinyl, and tile. NOTE: while casters perform perfectly on hard surfaces, they may require more effort on carpets, especially high-pile EXTRA STRONG AND RELIABLE - Engineered with advanced Inline Skates technology, our desk chair wheels are built for intense use. They incorporate a solid nylon frame and durable polyurethane casters, delivering exceptional strength and endurance. Capable of supporting up to 700 lbs, these wheels are perfectly suited even for heavy people, ensuring stability and long-lasting performance UNIVERSAL SIZE - Suitable for a wide range of chairs, the 2inch wheel size is perfect for maintaining normal chair height for optimal comfort across all user heights. The stem size is 7/16inch x 7/8inch - used by all popular brands of chairs in the US. Please note: These casters are not compatible with chairs. Check the stem size of existing casters before ordering to ensure compatibility The product has slight color differences, which does not affect use Colour:A:Black Material:PU Package Contents: 5 x Office Chair Wheels Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.