Office Chair Caster Wheels: Five-Piece Set That Is Sturdy And Secure On All ? PROTECT YOUR FLOORS AND MONEY?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 new 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! ? RELIABLE HEAVY DUTY CONSTRUCTION. 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. ? ENJOY SMOOTH QUIET GLIDING. Smooth and Quiet Rolling; Our precision ball bearings combined with vibration reducing polyurethane tires will give you a smooth and silent roll. They roll amazingly on hardwood floors, carpet, tile, concrete, stone or vinyl. ? DIFFERENT FROM TRADITIONAL WHEELS!: Have solved that traditional chair wheels get tangled with carpet, hair, and scratches on floors. Protect your expensive hardwood safe. ? USER FRIENDLY - Very Easy to Install; No tools required; Pull out your old office chair casters and push in your new wheels until stem is firmly seated and secure. - 1-year Warranty - Money Back Guarantee.(It is not compatible with I-K-E-A chairs, OUR STEM SIZE - 7/16" (11mm) x 7/8" (22mm))