System: equipment; other labels.vehicle description: transit and school buses equipped with caterpillar 3116 engine or hercules CNG engine that utilize and electrical preheating element.note: if you do not receive the warning decals or the warning decals do not correct the defect, please call thomas built service center at 1-910-889-4871.also, contact the national highway traffic safety administration's auto safety hotline at 1-800-424-9393.