New Soft Slide Formula (SSF) is faster rolling, and will outlast anything currently on the market by many times. Super fast, incredibly durable, and they slide. SSF is a new paradigm, opening up even more of our concrete and asphalt cityscapes, roads, and hills to skating. Essert Wheels: Larger 72mm diameter for more durability and grip. SSF PRO - 30% more grip than SSF. Pre-Ground surface for no break in time. Narrow contact patch at first for smooth slides. More volume / width than Snakes for more grip as the wheel wears. 2mm offset with new H5 core, still flippable for even wear.