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Rotary Dimmers by Forbes & Lomax

Finish: Unlacquered Brass


Forbes & Lomax’s Rotary Dimmers push to switch on and off and rotate to dim and brighten. The dimmers are based on the elegant nickel and brass switches of the 1930s. These simple, timeless dimmers are a refined detail in any interior.

Rotary Dimmers can be mixed with Toggle Switches and push buttons on the same plate. Contact us for custom configurations.

Established in 1987, Forbes & Lomax is a UK based company with a reputation for high quality design amongst architects and designers.


Knob: Ø 20 mm (0.79”)

1 Gang Plate: W 70 mm (2.76”) X H 115 mm (4.53”)
2 Gang Plate: 115 mm (4.53”) X 115 mm (4.53”)
3 Gang Plate: W 162 mm (6.38”) X 115 mm (4.53”)
4 Gang Plate: W 210mm (8.27”) X 115 mm (4.53”)

Available for:

  • LED: Max. 120W LED or 300W Incandescent/Halogen
  • Incandescent: Max. 500W Incandescent/Halogen
  • MLV Max. 600VA Magnetic Low Voltage Halogen (contact us)
  • 0-10V (Linear): Max. 20 0-10V Dimmable Drivers (contact us)
  • Non-Dimming: Max. 720W Any load types (ON/OFF only) (contact us)

See full Technical Specification sheets below.

Important Notes: 

  • Rotary dimmers conform to UL 1472 and are certified to CSA C22.2 No.184.
  • Please review and ensure all certifications are applicable for your local code.
  • Must be installed by a licensed electrician.
  • The dimmers are all supplied as 3-way and can also be used as single pole. A dimmer can only be wired at one locations on a three-way or four-way circuit. The other locations need to be non-dimming Toggle Switches.
  • LED dimmers are Forward Phase Triac dimmers, designed to control up to 120W of LED bulbs or 300W of incandescent bulbs. If you are dimming any larger wattages, or dimming any lights that have transformers or drivers, or have permanently built-in LEDs, we recommend you email us specifications on the lights so we can make sure they are compatible.
  • LED have on-board programming features to enable you to adjust the minimum and maximum dimming levels and adjust the dimming characteristics. This is often required when dimming LEDs. Once you install your dimmer, we recommend you follow the “optimizing your dimmer” instructions and then apply the “child lock” to retain the settings. It is important to note that the dimmers will not work with all LED light fixtures and bulbs. If you have any questions regarding the compatibility of our dimmers with the light fixtures you are using, please contact us.
  • Incandescent dimmers can control up to 500W of incandescent or halogen bulbs.
  • Rotary dimmers install into standard junction boxes but the boxes must be recessed below the finished wall surface by at least 1/8”. Please refer to the Wallbox Assembly Diagram in the Installation Guide below. If you are installing into existing junction boxes, you will probably find the boxes are already recessed by at least this much but please check to make sure before placing an order.

Areas of application: Light-duty Commercial, Residential


  • Unlacquered Brass
  • Aged Brass
  • Nickel Silver
  • Brushed Stainless Steel
  • Antique Bronze

Note: materials will slowly age or oxidize over time. Wipe clean with a dry, non-abrasive microfiber cloth. Avoid use of chemical or alcohol based cleaners. Refer to the care guide below for best practices.

Lead Time

3-4 week lead time. Please contact us for more information or for stock availability.

Product Downloads

Rotary Dimmer Product Sheet
Rotary Dimmer Installation Guide
Forbes and Lomax Brochure
Forbes and Lomax Care Guide