B15 (SBC) LED Golf Bulb 4.9W 470lm Non-Dimmable - Daylight 6500K - JCB

A golf ball bulb is the small round lamp that goes where a full size GLS would look heavy: shaded pendants, bedside lamps, wall brackets and the smaller fittings that came with the room. This one draws 4.9W and gives 470 lumens, which the pack puts level with an old 40W filament bulb. The cap is B15, the small bayonet: two pins on a slim metal base, narrower than the common B22. At 6500K the light is daylight white, the coolest of the three temperatures normally offered, with no yellow warmth in it.

Daylight white is a working light rather than a settling-down one. It keeps whites looking white and stops cream walls drifting towards yellow, so it earns its place in a kitchen, a utility room, a home office, a garage or a hallway where you want to see clearly the moment the switch goes on. The pack quotes a colour rendering index above 80, which means fabric, food and paint colours read close to how they look in daylight. A 180 degree beam angle spreads the light around the bulb rather than pushing it forward, so it works in a shade or a globe as happily as in an open fitting.

There is no dimming here: the specification lists it as non-dimmable, so put it on a plain switch rather than a dimmer circuit, where a non-dimming lamp can flicker or buzz. It reaches full output the moment it is switched on. The pack prints a rated life of 10,000 hours, up to 10 years, and the energy label gives class F. Each unit is a single bulb, and the minimum order is 12, sold in multiples of 12. We list the same 4.9W golf bulb on the B15 cap in warm white 3000K if you want a softer light in the same fitting.

How do I tell whether my fitting takes B15 rather than B22?

Both are push and twist bayonet caps, but B15 is the small one at about 15mm across the metal base, while B22 is noticeably wider. Measure the old bulb's cap or take it with you when comparing.

Will it fit inside a small shade or a closed globe?

The pack prints the lamp at 45mm across and 80mm long, so measure the opening and the internal depth of your shade before ordering if space is tight.

Can I use it on a dimmer switch?

No. It is listed as non-dimmable, so it needs a plain on and off switch. On a dimmer circuit a non-dimming lamp may flicker, buzz or fail early.

Is 470 lumens really enough to replace a 40W bulb?

The pack rates it as a 40W replacement, and 470 lumens is the usual output for that swap. It draws 4.9W to do it, so running cost drops sharply.

What does 6500K daylight look like compared with warm white?

It is a crisp, slightly blue-white light that suits close work and food preparation. Warm white at 3000K is softer and more yellow, and reads as cosier in a living room.

Does it need time to reach full brightness?

No. It comes on at full output straight away, unlike older compact fluorescent lamps that took a minute or two to brighten in a cold room.