2015-19. Bushing kit. Left.2015-19. Right.2015-19. A cover, typically made of plastic or rubber, which protect the Disc Brake Caliper guide pin heads from dirt, debris and moisture, to prevent corrosion. A Kit containing Disc Brake Caliper guide pin boots. Disc Brake Caliper Bushing. Disc Brake Caliper Hardware Kit.. Guide Pin Cover. Hardware. Slide Pin Boot. Included with: Caliper.