The unique SPORT SACT System - Straight And Cornering Technology - is another example of Bridgestone's intensive research and development. It's the perfect choice for the sporting rider seeking mileage and value for money. The key to the SPORT SACT success is a process called Dual Compound Construction. By combining two different rubber compounds, the result is a tyre which delivers long-wearing durabillity for upright everyday riding, plus aggressive shoulder grip when cornering. So at last there is a tyre which wears to the way you ride, with traction enhanced shoulders and a mileage boosting center line.