G4 & GU4 / MR11 Bulbs

G4 bulbs / GU4 MR11 bulbs

Small bulbs. Big impact.

G4 and GU4 bulbs might be small in name and size, but they’re big on impact, especially in the living room, hallway and kitchen.

What are G4 and GU4 MR11 bulbs?

Both G4 and GU4’s are low-voltage bulbs. The GU bulbs are usually created with a reflector with 11/8 inch diameter, designated with the suffix MR11.

However, please be aware that G4 and GU4 are often confused, even though they’re not identical. Although both have a pin spacing of 4 mm, the diameter of the pins in a GU4 bulb is slightly larger, measuring between 0.95 to 1.05 mm when compared to the G4’s 0.65 to 0.75 mm.

g4 bulb by Osram

G4 bulb without a reflector.

GU4 light bulb

GU4 MR11 bulb with reflector.

Where are G4 and GU4 MR11 bulbs used?

As G4 and GU4 MR11 bulbs are small and compact, they’re most often used in recessed ceilings and furniture (like fireplaces) or as under-cabinet lighting. Some designers even tailor their creations solely for G4 and G4U bulbs, including The Telchisugiò by Catellani & Smith and the Drop by Alma Light Barcelona.

g4 gu4 mr11 bulbs under cabinet lighting Paulmann Mirco Line
The most popular place for using G4 & GU4 MR11 bulbs is in recessed furniture and ceilings.
Almalight pendant light Drop
A whole 37 G4 bulbs illuminate the Drop pendant lamp by Cristian Cubiñá.
Catellani Smith led wall light with gu4 mr11 bulb
The aluminium body in gold leaf optic of the Telchisugiò is illuminated with GU4 MR11.
GU4 MR11 reflector
Close-up of the GU4 MR11 reflector of the Telchisugiò.

What are the benefits of the new G4 / GU4 LED bulbs compared to halogen?

New G4 / GU4 LED bulbs are compatible with all conventional G4/GU4 sockets, but the LED variant offers some improvements, including:

  • Less energy consumption with the same brightness
  • Longer service life
  • Higher switching strength

The changeover is particularly worthwhile if, for example, several downlights in your hallway or living room were previously operated with G4/GU4 halogen bulbs.

In instances like this, LEDs can save you a lot of money and reduce your carbon footprint.

next Drop pendant light

What is the difference between G4/GU4 and GU5.3?

The difference between the bulbs lies in the pin spacing. GU5.3 pins have a spacing of 5.33 mm and a larger reflector size, indicated by the following MR.

Both are low-voltage bulbs, but GU5.3’s are used more in spotlights, spots and surface-mounted ceiling lights.

g4 led bulb by Osram
Modern G4 LED light source
Philips GU4 reflector bulb
Modern GU4 MR11 LED reflector

Do you need good advice on suitable G4 / GU4 MR11 light bulbs? Or do you have another question about light and lighting? Then our team of experts will be happy to help you. Just fill in our contact form.

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