Tie Down Stainless Steel Disc Brakes "G5" DesignSingle position aluminum caliper, patented bimetal aluminum/stainless piston, oil impregnated bronze bushings, ceramic pads with stainless steel backing plates, stainless steel slider pins, GalvX coated hub and galvanized mounting bracket.Features/Specs: Precisions bearings, seals, Lucas Grease installed; Factory pre-installed stainless steel slider pins; Stainless Steel rotor with venting holes for faster cooling ; 5 on 4 1/2" bolt pattern, 2 kits required per axle;