Hello It is much greater the luminosity of the external round lamp of Leds 18 watts, in my house I placed one in replacement of a circular of 32w that had under a fan (in a bell). It has a transom that is screwed to where you want to place it and two lateral screws, without doubt is the replacement of the circular fluorescent of 32W, do not hesitate. They are placed if you want directly under the fans piercing said crossbeams. regards