The Gaither Tool Smart Tire Cart, No. G471147HD, moves mounted tires, wheel sets and stacks eight to 10 high. The Smart Tire Cart stacks tires close together, which allows for more storage space. It can be used to load and unload trucks and containers. The patented tilting action and the push/pull system, which pushes the tires out of the cart's arms, relieve stress off the user, according to the company.The cart works with 15" passenger tires up to truck size 245/70R19.5.