Product Material and Contents:wheelchair wheels replacementThe product is made of polyurethane foam, model 24 "x1" universal no-flat polyurethane tires, including (two tires, and mounting tools and mounting straps),adaptability:Compatible with nine-spoke 24-inch plastic wheels on all brands of wheelchairs. However, please note that it is not compatible with the vast majority of wire wheel sets.,SIZE ISSUE: Solid wheelchair tires will be smaller than the wheelchair wheels, which is normal, but will fit perfectly on 24" plastic wheels. Because the tire needs to fit snugly on the rim, there is no risk of the tire falling off once it is mounted.,Installation: Because the size of the tire is slightly smaller than the size of the wheel, so the installation requires a certain amount of force, we need to install with the help of a crowbar, you can soak the tires in hot water for 10 minutes, and then in the installation, this will save your strength, as well as more convenient installation!,Aftermarket Programs:There are many ways to install solid tires, you can refer to the online video tutorials as well as the methods we provide to install them, please feel free to get in touch with us through Amazon when you need it, we will provide a solution for your problem, within 6 hours.