Cooper Discoverer HT3 All-Season Radial Tire - 31/10.50R15 109R Tire only Continuous shoulder rib provides superior resistance to irregular wear for longer life and a quieter ride. Interlocking tread elements provide improved handling. Increased lateral slots increase traction in both wet and snow conditions. 3D Micro-Gauge siping provide an interlocking geometry to increase tread element stability for improved vehicle handling and all-season performance.