STRONG MATERIALS - Made of high-quality rubber and steel materials, the solid rubber flat free tire is strong, wear-resistant, impact-resistant, puncture-resistant, and can provide strong durability and long service life. The maximum load weight of the two wheels is 350 lbs. ROLL SAFELY AND STEADILY - Compared with pneumatic tires, our solid rubber wheel have a more durable and stable structure. Rugged and steep terrain is not a problem for solid rubber tires. It will not puncture or deform but has the same bounce and feel as a pneumatic tire.