The chair casters are easy to install, no tools required. They protect your floors from scratches and marks. No need for chair mats! These casters transform your simple task chair into a modern, stylish striking furniture. Universal caters will fit 99% of all standard office chairs sold in the U.S. (7/16"" wide stem). Very easy to install. Pull out the old chair casters and push in your new wheels, till they are firmly seated and secure.? The precision ball bearings in the caster swivel, provides the quit rolling without compromising its durability. They can support up to 650 pounds. The chair wheels are easy to install and no need for any tools.? Let the smooth gliding be the new normal. Sold as 5 pieces/Set.Sold as 5 pieces/Set.The chair casters are easy to install, no tools required. Very easy to install. Pull out the old chair casters and push in your new wheels, till they are firmly seated and secure.They protect your floors from scratches and marks. No need for chair mats!.These casters transform your simple task chair into a modern, stylish striking furniture.