Round profile with micro-siped knobs and carbide studs for traction on ice. The spikes work best on ice when running at minimum pressure while at maximum pressure the tires can be ridden on ice-free roads with minimal road noise. *To ensure proper spike seating the tire should be run for roughly 25 miles on asphalt while avoiding fast acceleration or hard braking. SGRD - Smartguard equipped tires feature a 5mm breaker belt made from special Indian and partially recycled rubber