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4mm pin spacing, commonly used in desk lamps, accent, display, landscape fixtures, and general lighting.

Click to read more about the G4

Brief history:

The bi-pin was created by Canadian inventor Reginald Fessenden working for Westinghouse in the late 19th Century when Thomas Edison would not allow another electrical company the right to use his screw-base light bulb design. The bi-pin was then patented to overcome this restriction and provide power to the 1893 World’s Fair in Chicago. In modern times, bi-pins are used in halogen fixtures and some types of fluorescent lights.

The G in the name dates back to when the bulbs were originally made from glass, though this is less the case these days, especially with LEDs. The 4 in G4 represents the 4mm gap between the pins. Standard G4 LEDs operate on 12V DC voltage.

How they’re used:

G4 light bulbs can provide omnidirectional lighting in small spaces, making them the ideal choice for lighting projects where space is limited. G4 LED bulbs are mostly used for chandeliers, recessed, task, decorative, landscape, and other types of accent lighting. G4 light bulbs are used for smaller lighting systems with low voltage power supplies available.

Why you want them:

G4 LED bulbs are replacements for halogen bulbs. G4 LED bulbs (12V) are energy-efficient since they use less power than halogen lights. They also don’t release as much heat as halogens. The average life of a G4 light bulb is over 25,000 hours and doesn’t contain any toxic chemicals that can harm your health.

You can decide on the light intensity of your G4 light bulb. EmeryAllen supplies a wide range of LED lights. Generally, people focus on wattage when they measure the brightness of a bulb. However, it’s different for LED bulbs. The actual brightness of LED bulbs is measured in lumens. For example, a 2.4w G4 LED bulb with 150 lumens produces a similar light intensity to a 20w standard light bulb. G4 LED bulbs are also dimmable, allowing you to adjust the light intensity of a room for the ideal ambiance.

G4 Halogen bulbs can be replaced with G4 LED bulbs easily. There are a few things to consider when replacing your halogen light:

Voltage and Transformer:

A G4 LED bulb operates on a 12V DC. While the mains voltage around the world is 120 or 220-240 volts, you cannot directly connect the G4 led with this voltage. You would need a transformer to convert the voltage down to 12V, though existing 12V fixtures would have accounted for this.


While replacing 12v halogen lights with G4 LED bulbs 12v, you must ensure that the G4 light bulbs are compatible with the lighting fixtures, and not a different style 12V bulb.


Do not forget to check the wattage of the fixture where the halogen lights were installed. Take note of your halogen wattage and find a compatible G4 LED at EmeryAllen. For example, a 20-Watt halogen bulb should be replaced by a 2-4 Watt G4 LED.

If you have any questions about our G4 bulbs or our other products, feel free to contact us.