GR10q LED 2D Bulb 13W 1500lm Non-Dimmable - Cool White 4000K

A 2D lamp is two folded tubes bent into a square outline with one base at the centre, and this is the LED version of that shape. The cap is GR10q, the four pin type, and the lamp runs at 13W for 1500 lumens at 4000K. That is a cool white: clean and neutral, with none of the yellow of a 2700K lamp, which is why it has long been the default in stairwells and workrooms. The body is white throughout, the four pins set into a square block in the middle. The pack quotes the 1500 lumens in a narrow cone, so the output is pushed forward through the diffuser rather than wrapped all round the tube.

2D fittings are chosen where the light needs to be shallow and hard to knock, so you find them on hallway and landing ceilings, up stairwells and along communal corridors, and in garages, utility rooms, lofts and storerooms. The square bulkhead and the flat drum fitting both take this lamp. Before ordering, take the old lamp out and look at the base: the two pin GR8 version will not seat in a four pin holder, and the four pin GR10q will not go into a two pin one. Count the pins, not the wattage.

There is one job to do before fitting. The pack states that the lamp is not compatible with an electronic ballast: the ballast has to be removed and the fitting rewired direct to mains, by a qualified electrician working to BS7671. The pack prints a 30 year lifespan and an energy class of E. It is marked non-dimmable on the pack, so leave it on a plain switch rather than a dimmer. Each listing is one lamp, with a minimum order of 10 in multiples of 10. It sits alongside our 2G11 PLL and 2G7 PLS LED lamps in cool white 4000K.

Will this fit my existing 2D fitting?

Only if the holder takes four pins. This is a GR10q cap, so pull the old lamp out and count the pins at the base: two pins means GR8, and this lamp will not seat in it.

Does anything need changing in the fitting before I use it?

Yes. The pack states the lamp is not compatible with an electronic ballast, so the ballast must be removed and the fitting rewired direct to mains by a qualified electrician working to BS7671.

Can I run it on a dimmer switch?

No. The retail pack marks it non-dimmable, so it wants a plain on and off switch. Wired to a dimmer it may flicker, buzz or fail well short of its rated life.

What does 4000K cool white actually look like?

Neutral and bright, closer to daylight than to candlelight. It keeps whites looking white and colours honest, which suits hallways, stairs, garages and anywhere you are working rather than relaxing.

What IP rating does it carry?

The manufacturer does not state one for this lamp, so we make no claim. Protection against dust and moisture comes from the enclosure it sits inside, and that enclosure's rating governs where it can go.

Which fluorescent 2D wattage does it replace?

The manufacturer prints no equivalent wattage, so compare lumens instead. This lamp gives 1500 lumens, and the pack notes that figure applies in a narrow cone rather than all round.