Brightness equivalent to 30W halogen. Due to the wider viewing angle much more even illumination of the room. Have these LED bulbs will replace a total of 12 halogen bulbs and am thrilled with the uniform color temperature of the LED lamps both pro and between the bulbs. Color temperature is almost identical to that of halogen. Differences even in mixing of halogen and LED barely perceptible. With direct replacement of all halogen, make sure that the minimum load is reached (specified as "10-60W") of the existing transformers, otherwise there will be occasional light flickering. So you need not "LED transformers" as long as one operates the present transformers properly. Example of a complete replacement of all halogen lamps with LED: 5 x 3.5 W = 17,5W total load at 5er Lichterkette only with LED, original transformer with 40 - 120W flicker let the LEDs. Having another transformer connected with 10-60W, the flickering was gone. Have been half year GU4, 2.4W (20W halogen replacement for), also of sebson, operation and am still very happy, so now the replacement of the same company.