Hi-Run Sawtooth 4.10/3.50-4 4PR Wheel and Tire Assembly, pre-mounted on a 4" x 2.5" steel wheel. Serrated tread provides reliable traction on concrete, gravel, or wet surfaces—300 lb (136 kg) load capacity, 30 psi max. Ideal for folding carts, balcony carts, and small utility carts.