Eco Light Bulbs

Today you will learn about Eco light bulbs which give a lot of light in very low energy.

Would you like to learn how light bulbs are made?

Fitting: What cap fitting do you need?

The first consideration when buying a light bulb is making sure that it will fit the light fitting correctly. To help you find the light bulb you need, they’re grouped by cap fitting.

A cap fitting feeds an electrical connection to your light fitting and ensures that it’s held in the correct position.

Common cap fittings explained


Bayonet capB2222mmThe UK’s most common cap fitting with a push, twist and lock action. Commonly written as BC.

Small Bayonet capB1515mmSmaller version of B22 with a push, twist and lock action. Also known as SBC.

Edison screw capE2727mmAnother regularly used cap fitting with a screw in action. Commonly written as ES.

Small Edison screw capE1414mmSmaller version of E27 with a screw in action. Also known as SES.

GU10 bulbsGU1010mm (between pins)Not dissimilar from a bayonet cap, these types of bulb have a push, twist and lock action. Used in spot lighting.

How to find the right cap fitting

If you’re replacing a bulb that has come to the end of its life, check the old bulb carefully for a name. If it doesn’t have one, have a look at the base and match it with our cap fitting table below:

If you need to buy a bulb for a new fitting, check the lighting packaging information for details of compatible bulbs and match it with our cap fitting table.

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