Varilight V-Pro Series Dimension Screwless Brushed Steel, 4 Gang (Quad), 1 or 2 Way 4x250 Watt Push on/Push off (Trailing Edge) Dimmer with Brushed Steel Knobs Eliminate Dimmer Buzz For GLS Bulbs, GU10 Lamps, and LV Transformers Including Trailing Edge Loads. The VARILIGHT V-Pro (Professional Universal) Series Dimmer (also known as the J Dimmer), like all our products, is designed to meet the latest European Safety Legislation. The V-Pro Series, eliminates Dimmer Buzz For GLS Bulbs, GU10 Lamps, and LV Transformers Including Trailing Edge Loads and is equipped with Self Re-setting Overload Protection, so is able to handle overload situations, for example, if the wattage of the bulbs/lamps are accidentally too high on a circuit. This is achieved by either, stepping down the dimmer\'s output to the lamps (if the watts are marginally overloaded), or the dimmer cuts out before there is any damage, (if the watts are grossly overloaded), until the load is reduced. The dimmer also contains a heat sensor which again stops damage to the dimmer, if it becomes too hot. The V-Pro Series Dimmer has Soft Start Technology, allowing a longer life span of the bulbs or lamps used by increasing the brightness level softly, which also creates a welcoming effect.  The V-Pro Series were primarily designed for Dimmable LED\'s, the dimmers, with a minimum load of only 10 Watts, can operate at least 1-20 good quality Dimmable LED\'s. These Dimmers can also be used to operate upto 12 Varilight (YCA20D) or Megaman Dimmable Energy Saving Lamps, (Please refer to the instruction leaflet of the Megaman lamps for usage tips). The V-Pro Series Dimmers can also be used for Mains Voltage Lighting, Trailing Edge Loads, and Electronic Low Voltage Transformers. When using Electronic Low Voltage transformers we recommend that a maximum of 5 good quality dimmable electronic transformers are used (10 if Varilight) with this Dimmer range. Please note: add the watts of the bulbs/lamps if using Varilight Transformers, to determine which dimmer to select, but if using another manufacturer of transformer, add up the VA of the transformers so it does not exceed the maximum of the dimmer.  The V-Pro Series Dimmers can also be used for mains incandescent GLS lamps (standard mains light bulbs), GU10 Lamps or similar Hi Spot Mains Halogen lamps, (only use quality UK supplied lamps), up to the maximum load as specified on the dimmer.