requires a compatible TRIAC dimmable switch for dimming function 4W,400lm,Warm white(2700K) light,create a warm and comfortable environment,ideal for family use. Combining advanced technology with retro design, isuitable for pendant lamp, ceiling fan, wall lamp, desk lamp and pillar lamp. Very low energy consumption,saving up to 80% energy, perfect replacement halogen or incandescent lamps. High quality filament, up to 10,000 hours service life.High color rendering (CRI > 80) provides vivid colors and additional warming effects.