4W Dimmable G9 LED Capsule Bulb - 2700K Warm White

The Knightsbridge G9LED16 is a 4W G9 LED capsule bulb designed as a direct replacement for traditional 28W-40W G9 halogen capsules. The bulb produces 390 lumens at 2700K warm white and is dimmable with both trailing and leading edge dimmer switches, subject to dimmer compatibility testing before installation.

G9 capsules are commonly fitted in decorative wall lights, bathroom mirrors, under-cabinet lighting, cooker hood lighting, and modern chandeliers where small bulb size is needed. This LED version reduces energy consumption from 28-40W down to 4W while delivering comparable brightness to a standard halogen. The 270° beam angle provides wide light distribution suitable for both direct and diffused fixtures.

The capsule measures 19mm diameter by 54mm height, fitting most G9 fittings without mechanical clearance issues. The ceramic and polycarbonate construction handles heat build-up better than all-plastic alternatives, and the clear diffuser allows the SMD LED array to be visible when lit. The bulb carries an IP20 rating for dry indoor use and is rated to L70B50 of 25,000 hours, meaning 70% of bulbs in a batch will still produce at least 70% of initial lumens after 25,000 hours of operation.

Knightsbridge rates this bulb as compatible with most trailing and leading edge dimmers, but dimmer compatibility varies between dimmer models and the total load on the circuit. Testing with your specific dimmer before completing a full installation run is recommended to confirm smooth dimming performance without flicker or minimum-load issues.

Product Specification Sheet

What wattage halogen does this replace?

This 4W LED capsule replaces 28W-40W G9 halogen bulbs while producing comparable light output at 390 lumens. The exact halogen equivalent depends on the beam angle and efficiency of the original halogen, but most users find this bulb matches a standard 33W halogen capsule.

Is it compatible with all dimmers?

The bulb works with most trailing and leading edge dimmers, but compatibility varies between dimmer models and the total load on the dimming circuit. Knightsbridge recommends testing with your specific dimmer before installing multiple bulbs. Some older dimmers designed for high-wattage halogen loads may require a minimum load adapter or replacement with an LED-compatible dimmer.

Will it fit my existing G9 fitting?

At 19mm diameter and 54mm height, this capsule fits most G9 fittings without clearance issues. However, some decorative wall lights and bathroom mirror lights have shallow housings or tight glass covers that may not accommodate the 54mm length. Measure your existing halogen capsule before ordering if space is tight.

What is the L70B50 rating?

L70B50 of 25,000 hours means that after 25,000 hours of use, 70% of bulbs in a production batch will still produce at least 70% of their initial 390 lumens. This is a standard LED longevity metric and represents approximately 10 years of typical domestic use at 7 hours per day.