Light Bulbs & Fluorescent Lights

E27

 27 mm in diameter, this is one of the most common fittings. It’s used by almost every light source with a voltage of 230 V, i.e. classic incandescent lamps, halogen, energy-saving, and LED bulbs. You can usually find this type in ceiling or wall lighting fixtures or chandeliers.

E14

 Has the same screw as E27, so once again, it’s used in classic incandescent lamps, halogen, energy-saving, and LED bulbs. They differ only in diameter, which in this case is 14 mm. The operating voltage is 230 V. Commonly used in smaller lamps, spot lights, and candelabra and chandeliers consisting of a large number of light bulbs.

GU10

 This slot has no screw. Instead, it has two pins with a diameter of 5 mm that you snap into the lamp and twist slightly. Its operating voltage is 230 V and this type is most commonly encountered in halogen or LED bulbs. It is used in ceiling lights, spot lights, or in bathroom and lavatory fixtures.

G4

 A threadless socket, it features two pins 4 mm apart that you snap into the lamp. Its operating voltage is 12V. Most commonly found in kitchen counter lighting fixtures, low ceilings, or bars.

GU5.3

 Another threadless socket, it features two pins 1 mm in diameter and spaced 5.3 mm apart. The socket is designed for 12V. The light source is usually a halogen or LED bulb. Mainly used in smaller lamps and spot lights.

G9

 A threadless socket similar to GU10. It has two pins that snap into the lamp. This is the smallest size for 230V halogen and LED bulbs. Most commonly used in ceiling fixtures, spot lights, or in bathroom and lavatory fixtures.

R7s

 A linear, tube-shaped socket inserted into a fork with a pitch of 78-189 mm. Its operating voltage is 230 V. Used in halogen spotlights, LED lamps, floor lamps, or architectural lighting fixtures.