LED Spotlights are designed to replace your existing halogen range. LED lighting is highly efficient as it uses 90% less energy than the traditional lighting sources - saving you more money. We aim to make choosing which product is right for you as easy as possible; whether you\'re looking for a particular size, colour, wattage or lumen output. 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.