Our dimmable lights have their own driver, which adapts the brightness & color temperature and can be controlled via the enclosed remote control & smartphone app. An external dimensional switch cannot control the brightness of the lamp, rather there are conflicts between the driver and external dimmer, which means that the light can no longer be controlled. So we recommend that you do without an external dimmer. In our lamps that have interchangeable lamps, there is no transformer, which means that the lamp can be dimmed over an external dimmer. The information that the lamps are interchangeable can be found on the product page of the respective lamp.