Brand New Race-Driven MudRat Rotors and Severe Duty Sintered Metal Brake Pads. You will receive 2 brake rotors and 2 sets of brake pads to replace the front brakes on the following: 2017 Polaris Sportsman SP 850. The MudRat Rotor is made from tempered stainless steel and is a solid rotor design which keeps mud and other abrasive materials from filling in the vent holes and prematurely wearing your brake pads. These rotors are designed to be used in 90% mud grade or higher. If you are an aggressive mud rider this is the rotor for you. Race-Driven Severe Duty Brake Pads are a sintered metal pad which will far out last any semi metallic or organic pad on the market, these pads will work excellent in all conditions. Race-Driven is committed to bringing the highest quality products to all riders at an affordable price. Customer Driven – Quality Driven – Race-Driven.