NOTE: AC/DC voltage 12V-24V: the bulb can be used directly AC voltage 100-240V: need to connect a compatible transformer Small size 35*35mm, please check the compatibility in advance, thank you very much!Using the Transformer: Electronic Transformer: The connected bulbs must reach the minimum output power of the transformer , otherwise the bulb will flicker. The flickering problem can be solved by installing a capacitor (in parallel with the circuit). LED transformer: no problem 85% Energy Saving GU4 MR11 12V 4W is an ideal substitute for GU4 35W halogen lamp, saving energy consumption more than 85%. The average life is 30,000 hours. LED lighting is energy efficient and efficient! 35mm MR11 GU4 LED 12V MR11 recessed LED spotlight with GU4 base, small size 35*35mm, easy to install. Before buying it, check that it is compatible with your lighting equipment. Ideal for kitchen furniture, bathroom, display case, dining room, caravan, etc. Warm White 3000K - 400LM LED spotlight MR11 GU4 12V 4W warm white 3000K, 24 SMD LEDs, 400 lumens with a 120 degree beam angle. No noise or flicker. CRI>80Ra, vivid and natural colors. This GU4 LED is not dimmable, is not compatible with dimmers.