describe Works on all floor types - stop damaging expensive floors. Many chair casters use cheap, hard, low-quality materials that can damage floors. We don't do that. Our wheels are designed with a soft polyurethane material that ensures no scratches or marks on any surface. Now you too can ditch that ugly cushion and upgrade to an office chair! A LIFETIME DURABLE PRODUCT - The entire bracket and internal parts are made of high-quality steel for easy use and durability. The heavy-duty design supports groups of 5 up to 650 kg and is one of the strongest chair casters available. Enjoy a smooth, quiet ride - stay focused and relaxed with these wheels. Precision ball bearings in the wheel pivots and axles ensure smooth rotation without any noise or noise that would distract you from your most productive moments. Modern, Unique and Stylish: These casters are designed with a standard size universal stem (11mm) so you can transform any task chair into a contemporary piece of furniture.