E27 (ES) LED GLS Bulb 13.8W 1521lm - Cool White 4000K

A GLS is the classic household bulb shape, and this one takes the larger E27 screw cap, also marked ES. It draws 13.8W and gives 1,521 lumens, which the pack rates against a 100W conventional bulb, so it sits at the bright end of what one ceiling fitting usually carries. The light is cool white at 4,000K: a clean neutral that reads whiter than the 2,700K most homes are used to, without tipping into the blue of a 6,500K daylight lamp. The dome is diffused white rather than clear, and the beam angle is 200 degrees, wide enough to fill a shade evenly.

Cool white at this output suits rooms where you are working rather than winding down: a kitchen with worktops to see, a utility room, a garage, a home office or a hallway that gets little daylight. It fits pendants, table lamps and ceiling roses wired for the big screw cap. Check the old bulb first, because E27 is noticeably wider than the E14 small screw used in many smaller lamps and chandeliers. It is also worth changing a whole room at once: 4,000K next to 2,700K shows up straight away.

The specification lists this bulb as non-dimmable, so keep it on a plain on/off switch rather than a dimmer circuit. The pack prints a 10 year lamp life and 10,000 hours, plus more than 10,000 switching cycles, so it copes with a landing or hall light that gets flicked on and off all day. It is rated IP20, which means no protection against water, and the energy label reads class E. One unit is a single bulb, and the minimum order is 5, sold in multiples of 5. Our wider range runs to candle, golf and filament GLS bulbs in screw and bayonet caps.

How do I know if my light takes an E27 cap?

E27 is the wider screw thread, about 27mm across, and it is often marked ES on the old bulb or the fitting. If the thread on the bulb you are removing looks small, closer to 14mm, you need an E14 instead.

Can I use this on a dimmer switch?

No. The specification lists it as non-dimmable, so it belongs on a standard on and off switch. Fitted to a dimmer it may flicker, buzz or fail early, so choose a dimmable lamp for that circuit.

Is 1,521 lumens bright enough to replace a 100W bulb?

Yes. The pack rates this 13.8W lamp as the equivalent of a 100W conventional bulb, so a single one is enough for a kitchen ceiling, a garage or a large hallway.

What does 4,000K cool white actually look like?

It is a neutral, slightly crisp white with no yellow cast. Worktops, paperwork and tools read clearly under it, though it feels cooler than the 2,700K or 3,000K bulbs used in most living rooms.

How many do I have to buy, and what comes in one unit?

Each unit is one bulb in its own retail box, and the minimum order is five, in multiples of five. That suits doing a whole room at once and keeping a spare or two by.

How long should it last before it needs changing?

The pack prints a 10 year lamp life at 10,000 hours, with more than 10,000 on and off cycles, so frequent switching in a hall or on a stairwell is not a problem for it.