ProStop Brake Rotor (31251G) ProStop brake rotors are designed for optimal stopping, longer life and greater resistance to warping. Non-directional rotor surface finish is ready to install with no turning required All ProStop brake rotors follow OEM specifications for iron plate thickness and air gap. Vent rib count, size and pattern matches OEM specifications and promises perfect fitment. OE Design including weight and cooling fin configuration to deliver good dependable braking.