Firestone Winterforce Winter Radial Tire - 235/55R17 99S Severe Snow Performance - Meets the severe snow service requirements of the Rubber Manufacturers Association (RMA) and the Rubber Association of Canada (RAC) Pinned for #12 studs - Extra traction potential Directional Tread Pattern - Optimizes wet and dry performance through tread design High-sipe density - Latest in high-sipe density, three-dimensional tread patterns for confident snow, wet and ice traction. Mud and snow rated. In ice and snow conditions, lower speed rated winter tires provide better traction, braking and cornering performance than higher speed rated touring and performance all-season radial tires. Therefore, lower speed rated winter tires are an acceptable replacement for higher speed rated tires when used for winter conditions.