Energizer 4.9W GU10 LED Bulb 4000K Cool White Non-Dimmable - 4 Pack

The Energizer 4.9W GU10 is a non-dimmable LED spotlight bulb producing 345 lumens at 4000K cool white colour temperature. Each bulb measures 50mm diameter by 54mm height and fits standard GU10 twist-lock fittings found in recessed downlights, track lighting and adjustable spotlights. The 38-degree beam angle focuses light into a defined pool rather than wide-angle wash, making these bulbs suited to task lighting and accent positions.

Designed for kitchens, bathrooms, utility rooms and home offices where cool white light supports task work, the 4000K temperature sits between warm white (2700-3000K) and daylight (5000-6500K). The light reads as neutral rather than yellow-toned, which helps with colour accuracy when cooking, applying makeup or reading documents. The non-dimmable driver delivers consistent output without flicker, though these bulbs cannot be paired with dimmer switches.

Each bulb draws 4.9W to replace a 50W halogen equivalent, reducing heat output and electricity consumption by approximately 90%. The Energy Rating F reflects current EU labelling where LED bulbs now occupy ratings E-G following the 2021 rescaling that removed the old A+ to D bands. Despite the F rating, these LEDs still use significantly less energy than the halogen bulbs they replace. The four-pack format covers a typical kitchen or bathroom installation without needing to mix bulb batches.

Can these bulbs be used with a dimmer switch?

No. These are non-dimmable LED bulbs and must not be connected to dimmer switches. Using them on a dimmer circuit will cause flicker, failure or early burnout. If dimming is needed, look for bulbs explicitly marked as dimmable GU10 LEDs.

What's the difference between 4000K and warm white bulbs?

4000K cool white reads as neutral to slightly blue-toned compared to warm white (2700-3000K) which has a yellow cast. Cool white is better for task lighting in kitchens and bathrooms where you need to see true colours. Warm white suits living rooms and bedrooms where a cosier tone is preferred.

Will these fit my existing GU10 downlights?

Yes, provided your fittings take standard GU10 twist-lock bulbs. The 50mm diameter and 54mm height match the halogen GU10 form factor, so these will fit recessed ceiling downlights, track spotlights and adjustable wall fittings designed for GU10 bases.

How long do these bulbs last?

Energizer does not publish a rated lifetime figure on the packaging shown. Typical GU10 LEDs in this wattage bracket last between 15,000-25,000 hours depending on operating conditions. At three hours per day usage, that translates to approximately 14-23 years before replacement.