Industrial Grade tough coat shatterproof incandescents are engineered to last up to 10 times longer than standard light bulbs, therefore reducing operating and maintenance costs. Rough Service tough coat lamps contain a rubberized outer coating to prevent bulb shattering and comply with city and state fire codes. Equipped with a rugged 5 filament support, pure tungsten coil, reflector disc, and brass base, Industrial Grade shatterproof bulbs will burn continuously for an average life of 18 months in commercial applications and up to 6 years in basic household use.