Bulbrite's Rough Service Incandescent A19 lamps feature a heavy duty reinforced filament for increased durability Bulbrite's Rough Service Incandescent A19 lamps feature a heavy duty reinforced filament for increased durability. Ideal for restaurants and work areas. Available in clear and frost. Applications: Ideal for general purpose applications as well as restaurants and work areas. Why the 75A/CL/RS-2PK: Rough Service lamps feature a heavy duty reinforced filament for increased durability. Incandescent bulb for use in portable lamps, ceiling lighting and other household applications