I wanted to replace 2 halogen bulbs of 20 watts each. The lights are much brighter, so should the vote with the 40W equivalent. However, my mirror cabinet transformer like so many others, a minimum load. Therefore, the lights go out after a few seconds. Maybe I'll do items, another transformer. Currently, I manage myself so that I replace only one of the two bulbs by LED, which brings brighter light with less power and extends the base load for the transformer.