B15 (SBC) LED Golf Bulb 4W 470lm Non-Dimmable - Warm White 2700K

This is a golf ball bulb with a B15 small bayonet cap, drawing 4W and giving out 470 lumens of warm white light at 2700K. The glass is clear and the LED filaments run straight up the centre of the sphere, so the light source itself is part of what you see rather than something hidden behind opal glass. The pack rates it as an equivalent to a 40W incandescent golf bulb, and it carries an E energy rating.

B15 is the smaller of the two bayonet caps, and it turns up on wall lights, small pendants and multi-arm ceiling fittings. It is easy to mix up with the larger B22 bayonet, so it is worth taking the old bulb out and measuring the cap across the pins before ordering: two smooth pins on a 15mm barrel means B15, while a wider barrel means B22. At 2700K the light has the yellow warmth of an old filament bulb rather than the whiter cast of 4000K, which makes it comfortable in a sitting room, a bedroom or a hallway where you want the room to feel settled in the evening. Because the filaments are on show, it works best in a shade that leaves the bulb visible, or behind clear glass.

It is not dimmable, so give it a plain on and off switch; non-dimmable LEDs on a dimmer circuit tend to flicker or hum rather than drop their output. The pack prints a 15 year lifespan based on 15,000 hours of use, which at three hours a night is well over a decade. Each unit is a single boxed bulb, and the minimum order is 12, sold in multiples of 12. It sits alongside our other B15 (SBC) bulbs in 4.2W and 7.3W, including candle shapes in warm white 2700K and cool white 4000K.

How do I know whether my light takes a B15 cap?

Take the old bulb out and look at the base. B15 has two small pins on a smooth barrel roughly 15mm across, so it is noticeably slimmer than the common B22 bayonet found in most ceiling pendants.

Will 470 lumens really replace a 40W bulb?

Yes. The pack gives 40W as the equivalent, and 470 lumens is the output an old 40W golf bulb produced, so the room should look the same brightness for a quarter of the power.

Can I put this on a dimmer switch?

No. The specification lists it as non-dimmable, so it needs a plain on and off switch. Fitted to a dimmer circuit, a non-dimmable LED is liable to flicker, hum or refuse to start.

What does warm white 2700K actually look like?

It is the soft yellow tone of a traditional incandescent bulb. It flatters wood, warm paint colours and skin tones, and it reads as much cosier than a 4000K cool white lamp.

Is an IP rating given for this bulb?

No IP rating is stated by the manufacturer, on either the specification or the pack, so treat it as an ordinary indoor lamp for dry, enclosed or open fittings.

How many bulbs do I receive?

One unit is a single boxed bulb. The minimum order on this line is 12 units, sold in multiples of 12, so the smallest purchase is twelve bulbs.