Say Goodbye To Flat Tires: The 4.10/3.50-4 tire is made of high-quality urethane tires and iron hub. The flat free wheels can prevent from getting punctured or deflated. Keep you away from the trouble of inflating tires frequently. Please pay attention to check if your old tire model number matches before buying. (note:suitable for dynamic loads, but not for static loads) Widely Applicable: The 4.10 3.50-4 flat free tire are the most common size of tires used for home. Perfect replacement for your wheelbarrow wheel, hand truck tires, dolly tires, wagon tires, handtruck tires,dolly cart wheels, garden cart tires Scientific Design: Staggered serrated tread design and heavy duty double sealed ball bearings with 5/8” axle bore,scientific structural design and high-quality metal materials great.