B22 (BC) LED GLS Bulb 4.2W 470lm Dimmable - Cool White 4000K

This is a standard GLS bulb, the familiar rounded pear shape most ceiling pendants and table lamps were designed around, on a B22 bayonet cap. The two pins push in and twist a quarter turn, so if the bulb you are taking out has a smooth metal base with two small lugs rather than a screw thread, this is the one. It draws 4.2W and gives 470 lumens, which the pack puts level with an old 40W filament bulb. The colour is 4000K cool white, cleaner and slightly bluer than the yellower 2700K warm white, and the opal glass spreads it evenly rather than throwing a hard point of glare. One lamp comes in the box.

Cool white at this level suits rooms where you want to see clearly: kitchen ceilings, utility rooms, garages and workshops, a home office where paperwork gets read, or a hall pendant that has to work at seven in the morning. Most people still prefer a warmer tone in bedrooms and sitting rooms. The GLS shape sits comfortably inside a shade, so it is at home in pendants, standard lamps and table lamps alike, and the frosted look is quiet enough where the fitting leaves the bulb on show.

The lamp is dimmable. LED bulbs draw so little power that an older rotary dimmer built for filament lamps may not reach its minimum load with one 4.2W bulb on the circuit, so a trailing edge LED dimmer is the safer pairing. The energy rating is E and the pack prints a 15 year lifespan. Each box holds one bulb, with a minimum order of twelve in multiples of twelve, worth knowing if you are relamping a whole floor. Our wider range runs to warm white 2700K as well as cool white 4000K, with candle and golf shapes on the smaller B15 bayonet cap and GU10 lamps.

My old bulb screws in. Will this one fit?

No. This is a B22 bayonet cap, the two pin push and twist type. If the old lamp has a screw thread it is an E27 or E14 and you need that cap instead.

How bright is 470 lumens in practice?

It is the light of a traditional 40W filament bulb, which the pack states as the replacement figure. Plenty for a table lamp or a smaller room, modest for a large open kitchen ceiling on its own.

Will it work on my dimmer switch?

It is a dimmable lamp, so yes on a suitable dimmer. Older rotary dimmers made for filament bulbs often have a minimum load that a single 4.2W lamp cannot meet, so a trailing edge LED dimmer gives the smoothest result.

What does 4000K cool white actually look like?

Clean and neutral, closer to daylight than to candlelight. It suits task areas and working rooms. If you want the cosier yellow tone of a traditional bulb, choose a 2700K warm white instead.

Is an IP rating given for this bulb?

No IP figure is printed on the pack or listed in the specification, so treat it as an ordinary indoor lamp for dry interior fittings and nothing more.