LED bulbs are replacing traditional incandescent bulbs (section 5.1) or halogen bulbs (section 5.2) since they are preferable in terms of efficiency and energy savings (energy classes A to A). They usually have the same shape and socket as traditional bulbs (e.g. E27, E14, GU10, GU5.3 etc.), integrating LED diodes and electronics (driver) required to guarantee operation. Currently there are no official technical rules that regulate the operation of this type of bulb. Since the behaviour of light bulbs with integrated electronics is different from that of simple light bulbs, most manufacturers provide lists of compatible dimmers, which allow you to select the most suitable dimmer. It is advisable always to use transformers and dimmers specific for LED bulbs and to check whether they are compatible and operating properly. When using traditional dimmers, it is advisable always to check that they have been tested and approved by the manufacturers of the light bulbs you intend to use and the maximum number of LED bulbs that can be dimmed. In fact, these dimmers work with high minimum loads and do not read the low loads of LED bulbs: the electronics integrated in the light bulbs must be able to ensure the dimmer perceives the minimum load required. Therefore a dimmer that is not designed specifically for LED light bulbs might dim a smaller quantity of bulbs than a LED- specific dimmer would (e.g. a generic 300W dimmer can dim up to a maximum of 10 x 4 W LED light bulbs for a total of 40W, while a LED- specific dimmer with a maximum power of 100W can dim up to 25 up to a maximum of 100W precisely. LED lamps also contain various electronic components that, in unfavourable conditions, may generate acoustic noise. Catellani & Smith uses, recommends and checks the high-quality LED light bulbs of the leading suppliers on the market (e.g. Philips, Osram, Soraa, Idealed, etc.) and cannot guarantee the proper functioning of its luminaires with low-quality LED bulbs or those from unknown LED bulb manufacturers.