Caliper mount retainer kit. Front. Left.4WD. Right.4WD. A bolt used to Mount / lock the disc brake Caliper to the disc brake Caliper guide pin. A pin used with a float style Caliper, which Mounts the Caliper to a Caliper bracket through a Caliper guide pin bolt, allowing the Caliper to slide freely during braking. Disc Brake Caliper Bolt. Kit. Included with: Caliper.