S4.0 guards feature hundreds of perforations, which maximizes ventilation. The knee pad is soft, comfortable, and features D3O padding. These guards have a Quick-Clamp system, which reduces the straps for easy removal and install. The two straps that clip on the guard are reduced to one strap, which is less bulky behind the knee. These guards have lightweight and ventilated cushioning with optimized plate placement for the best performance.