This is a Replacement Kodiak Trailer Dacromet coated 10 inch Disc Brake Rotor. Kodiak part number ROTOR-10-DAC. This brake rotor is designed to slip over 5 Lug idler hubs with a 5 on 4 1/2 inch bolt pattern that have 1/2 inch studs. This slip on rotor goes over top of your hub, and then your tire and wheel goes on, and everything is tightened into place using the lug nuts. The Kodiak vented brake rotor measures 10.9 inch outside diameter. All Kodiak rotors are 100% tested and balanced. Kodiak on uses rotors that are vented to help dissipate heat faster. This rotor is for use with 14 inch or larger wheels. Kodiak also offers a 3 year warranty on all their dacromet coated parts.