Manufactured to the highest standards, the Energizer range is compliant with the latest industry regulations and includes high performance, economical and sustainable technologies. This particular spotlight is non-dimmable, however, we do have dimmable GU10 spotlights available in our spotlight categories. If you are choosing a dimmable LED, you may require a Trailing Edge dimmer switch. Please contact us if you’re unsure on your dimmer switch compatibility. MR16 units will only work on a 240v mains circuit when being powered by a compatible 12v transformer. Alternatively, the MR16 units can work on a dedicated 12V DC circuit without the requirement of a transformer. While these units are compatible with the majority of electronic transformers, we cannot guarantee compatibility for all. For optimum efficiency, we advise that you change your existing transformers to LED Drivers to guarantee compatibility. Please contact us for advice or assistance if unsure how to proceed.