The Discoverer STT PRO provides exceptional traction and performance in some of the harshest terrains. The distinctive tread design and compound provide remarkable on the road performance and off-road traction. 3-Ply Armor-Tek3 . silica tread compound . aggressive 3-2 center rib design . side-biters and more . all wrapped up in Cooper's advanced mud terrain tire. The Discoverer STT PRO features large cleats of rubber on the shoulder area of the sidewall . to enhance traction and grip. The inner tread ribs alternating 3-2 pattern provides a number of significant performance benefits like: reduced road noise . increased stability and handling . superior soft surface and mud traction.