100% Safe Protection for All Floors - Stop damaging your expensive hard wood floors and carpets. Encased with soft polyurethane material, our rollerblade style wheels are guaranteed not to scratch or leave marks on any surface. (Please note that with the limitation of 2in, using on the rug with wool over 2cm will be possibly unworkable) Strong and durable - Maximum weight rating: 110 lbs. EACH wheel. The all-metal bearing rod and the bracket made of high hardness polyurethane provide years effortless rolling and durability. The heavy duty design supports up to 550 lbs as a set of 5, the STRONGEST chair wheels on Amazon. Universal Fit &EASY Installation - Orders come with a set of five 2" rollerblade style office chair replacement wheels that can easily be installed without tools or hardware. Simply pull out old wheels and push these into place, Please Check that your chair is compatible. (The stem size is 7/16"(11mm) diameter by 7/8"(22mm) length)(exclude IKEA's)