★ SAFE FOR ALL FLOORS - Stop damaging your expensive hard wood floors. Many chair wheels use cheap, low quality materials that destroy your flooring. We don't. Encased with soft, polyurethane material our rollerblade style wheels are guaranteed not to scratch or leave marks on any surface. So feel free to finally toss that old computer chair floor mat! ★ CASTERS YOU CAN KEEP FOR LIFE - Entire support bracket and internal parts are made of high grade steel, providing years effortless rolling and durability. The heavy duty design supports up to 650 lbs as a set of 5, the STRONGEST chair wheels on Amazon. ★ ENJOY SMOOTH & QUIET ROLLING - Remain focused and relaxed with the help of these caster wheels. Precision ball bearings in the caster swivel and axel provide smooth, easy rolling while causing no squeaky sounds or noise of any kind.