Question: is mr11 same as gu4?
Answer: Halogen MR11 Bulbs (aka MR11 or GU4) The MR11 has 2 sharp pins on the bottom of the light bulb and is classed as a 'push-fit' light bulb. It is a 12V lamp which requires a transformer, but what makes it different from the MR16 is its width, which measures 35mm across the face of the light bulb.