1998 1999 Polaris Big Boss 500 6x6 Middle Severe Duty Brake Pads Race-Driven Severe Duty Sintered Metal Brake Pads. Race-Driven exclusive sintered metal compound is designed to withstand extreme conditions Excellent performance in mud, water, sand, racing and any other condition you can throw at them 1998 - 1999 Polaris Big Boss 500 6x6