Excessive heat can cause resins in your brake pad to vaporize or "outgas." As the brake pad wears, the used friction material turns into a fine dust. This boundary layer of heat, gas and dust builds up between the pad and rotor surfaces and inhibits performance. Here's where Power Slot's slotted brake rotors make a big difference.Power Slot's exclusive Vac-U-Slots are machined into the rotor and help evacuate gasses and dust, shed heat, and keep the brake pad surface clean. And in wet, raining conditions, PowerSlot Vac-U-Slot helps push water off the braking surface for better stopping power.These several key features make these a great rotor choice for street driving, and open track days!