Cooper Discoverer M+S Winter Radial Tire - 255/70R18 113S Tire only "Snow-Groove" design technology provides biting edges for excellent snow and ice traction without reducing tread element stiffness. "D Squared" sipe technology enhances winter performance while maintaining excellent wet traction. Sawtooth center circumferential rib and blocky tread elements enhance stability and even treadwear. Optimized tire profile shape evenly distributes contact pressure for balanced treadwear.