The R & BR lamp is incandescent lamp, it has heavy gauge brass base and extended life up to 130 volt versions. The BR's have even coating and side etch eliminate pinholes and shadow casting. The most commonly used lamps for recessed can lighting, the lamp has highest quality and are competitively priced.
Incandescent lamp has long life
Heavy gauge brass base improved heat dissipation
Long term reliability
Even coating eliminates pinholes that allow light to escape out the back of the lamps