At 85w this is a low energy CFL (compact fluorescent) helix spiral lamp that produces a lot of light. Think small-sun, amounts of light. OK so maybe that's exaggerating a little, but this lamp is the brightest low energy lamp we have ever seen. It blows everything else out of the water. With the consumption of 85 watts of power this lamp produces 5500 lumens, which is roughly the same as a 425w incandescent light. This light bulb has a BC (Bayonet cap, B22) lamp cap. This crisp white light is a good choice for any area where work is done e.g. Kitchens, Bathrooms, Offices, Studios. Also suitable to help with Seasonal Affective Disorder (SAD). These high output Green Lamp bulbs (45w - 105w) can sometimes emit a slight buzzing noise when they are in use. If you are using them as hi-bay replacement bulbs or will be some distance away from them when they're in use, then you are unlikely to notice anything but these bulbs might not be ideal for use in an otherwise silent room. The manufacturer have said that the buzzing noise does not in any way effect the lifespan or light output of the bulbs and is normal, but we at My Green Lighting wish to make you aware of the issue before you purchase as we cannot replace any bulbs which exhibit this behaviour.