Varilight Dimmer Switches have an industry-wide reputation for exceptional performance, long life and innovation at attractive prices. Like all Varilight products these V-Dim (Standard) Series dimmers are designed to meet the latest European Safety Legislation. The lights are dimmed by a rotary control knob and turned on and off by a push on/off action. V-Dim Push on/off dimmers are suitable for 1-way and 2-way circuits. V-Dim Series Standard Dimmers are Leading Edge and can be used with Mains Voltage Lighting and good quality Low Voltage Electronic 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. Please note that noise levels can depend on the quality of the transformer being used. The best suited dimmer series for dimming Electronic Low Voltage Transformers is the V-Pro Series, which has many features including Dimmer Buzz Elimination, that is created from the Transformers. If using 6+ non Varilight Transformers then choose the V-Pro or V-Plus Series. The V-Dim Series Standard Push on/off Dimmers can be used in 2-way circuits (where one lighting circuit is controlled from two locations). In order to achieve 2-way switching, they must be paired with a standard 2-way switch in the other location. 3-way switching can be achieved by adding an intermediate switch in to the circuit. The V-Dim switches are not suitable for use with LEDbulbs. 1 or 2 Way Dimmer Knob 100% tested and inspected Fully compliant with British Safety Standards Top quality high current components for extremely long-life Low noise operation Wattage  400 W Manufacturer Code  SIN-HQ3W Manufacturer DESC.  HQ3W