This is a 9 X 3.50-4 foam filled knobby tire. Foam filled tires are Primo pneumatic tires filled with urethane foam, so they are a tire inside of a tire. These are made for 2 piece wheels only, they are flat free. The bead to bead width is 2.30". Maximum rider weight is 250 lbs. Please watch our videos to make sure this is what you need. Sold as each.