Bulbs Selection Guide
Bulbs are divided into LED, candle, capsule, propeller and tube groups; reading the base code such as E27, E14, G9 and GU10 is the first step in determining compatibility with the luminaire.
This guide explains what to look at when choosing products in the Bulbs category.
Types of bulbs
- LED bulbs: standard, filament, rustic and torch models with E27, E14 and GU10 bases.
- LED candle bulbs: slim, candle-shaped bulbs with an E14 base; used in chandeliers and wall lights.
- LED capsule bulbs: light sources a few centimeters long with G9 and G4 bases; fitted into decorative luminaires with narrow bodies.
- LED propeller bulbs: high-lumen bulbs with a bladed body that fit an E27 socket.
- LED tube lamps: G13 base, 60 cm and 120 cm long, in the shape of a fluorescent tube.
- Lamp holders: corded GU10 lamp holder and GZ10 ceramic lamp holder.
How to read the base code
The base code is the first piece of information that determines whether a bulb will fit a luminaire.
- The letter E indicates a screw (Edison) base; the number next to it is the screw diameter in millimeters: 27 mm for E27, 14 mm for E14.
- The letter G indicates a pin base; the number is the distance between the two pins: 4 mm for G4, 9 mm for G9, 10 mm for GU10, 12.7 mm for G13.
- GU10 and GZ10 are twist-lock bases with the same pin spacing. A GZ10 lamp holder accepts a GU10 bulb, but a GU10 lamp holder does not accept a GZ10 bulb.
The base code does not settle the operating voltage. The G9 capsules in this category run on 220 V and the G4 capsule on 12 V; among the LED bulbs with an E27 base there are also models supplied with 12-48 V AC-DC. A low-voltage bulb is not connected directly to the mains; the luminaire must have a supply with a suitable output.
How many lumens to look for as a replacement for an incandescent bulb
European Commission Regulation No 244/2009 defined the following luminous fluxes for non-directional LED bulbs whose packaging states an incandescent equivalent:
- 470 lm for a 40 W incandescent equivalent
- 806 lm for a 60 W incandescent equivalent
- 1055 lm for a 75 W incandescent equivalent
- 1521 lm for a 100 W incandescent equivalent
Compare the luminous flux in the product data with these values; two LED bulbs of the same wattage can have different lumens. Spot (directional) bulbs that concentrate light into a narrow angle are outside the scope of this table.
Bulb or LED luminaire
GU10 bulbs are used together with spot housings; the housing and the bulb are selected separately. In integrated LED luminaires, on the other hand, the LED and the driver are part of the body; there is no lamp holder and no bulb is fitted.
Before fitting an LED tube lamp into an existing fluorescent luminaire, the tube manufacturer's wiring instructions should be consulted. Even when the base is the same, how the ballast and starter in the luminaire are to be handled varies by model.
Brands in this category
- ACK: standard and rustic LED bulbs (E27, E14, GU10) and the GZ10 ceramic lamp holder.
- Cata: filament, candle, capsule, tube and propeller bulbs; a remote-controlled RGB bulb and a rechargeable bulb.
- Dünya LED, NisaLuce and Atlantis appear with a small number of standard, torch, propeller and candle bulbs.
Order notes
The sales unit is the piece. ACK bulbs and lamp holders are sold in manufacturer cartons; the minimum order quantity equals the carton contents and is stated on the product page. By typing the model code in the product name (for example AA13-05020, CT-4229, HS1217) into the site search, you can go straight to the bulb you are looking for.
Comparison and selection table
| Selection Criterion | E27 / E14 Standard LED Bulb | GU10 / MR16 Spotlight Bulb | High-Wattage (T-Bulb / E40) Lamp |
|---|---|---|---|
| Base Socket | E27 (standard screw) or E14 (candle screw) | GU10 (230 V twist-lock) or GU5.3 (12 V bi-pin) | E27 or E40 Goliath screw base |
| Power & Lumen Output | 4 W – 15 W (400 – 1500 lm) | 4 W – 8 W directional beam (36°–110°) | 20 W – 60+ W (2000 – 6000+ lm) |
| Color Temperature | 2700K/3000K (Warm), 4000K (Neutral), 6500K (Daylight) | 3000K, 4000K, 6500K accent & recessed lighting | 6500K daylight or 4000K neutral white |
| Typical Application | Residential fixtures, pendants, wall sconces | Recessed downlights, retail & hospitality | Warehouses, workshops, high-ceiling bays |
Frequently asked questions
What is the difference between E27 and E14 lamp holders?
Both are screw-type Edison bases; the difference is the screw diameter. The E27 base is 27 mm and the E14 base is 14 mm in diameter, and one cannot be fitted into the other's lamp holder. E27 is common in general lighting luminaires, while E14 is common in small-bodied luminaires such as chandeliers, wall lights and lampshades. If you are not sure, look at the markings on the base of the old bulb or measure the screw diameter.
Does a GU10 bulb fit a GZ10 lamp holder?
GU10 and GZ10 bases have the same 10 mm pin spacing and lock by twisting. A GZ10 lamp holder accepts a GU10 bulb; a GU10 lamp holder, however, does not accept a GZ10 bulb. The distinction comes from halogen bulbs: the GZ10 base was defined for bulbs with a dichroic reflector. When choosing an LED bulb, rely on the code printed on the lamp holder in the luminaire.
What is the difference between G4 and G9 capsule bulbs?
The number in the code indicates the distance between the pins: 4 mm for G4, 9 mm for G9. The two bases do not fit into each other's lamp holders. The G9 capsules in this category run on 220 V mains voltage and the G4 capsule on 12 V; for G4, the luminaire must have a transformer or driver with a 12 V output. When replacing, match both the base code and the voltage with the old bulb.
Can an LED tube lamp be fitted into an old fluorescent luminaire?
G13 is the two-pin base that T8 fluorescent tubes also use; this category has 60 cm and 120 cm G13 LED tubes. However, a fluorescent luminaire has a ballast and starter, and how the LED tube is to be connected with them varies by model. The replacement should be done according to the tube manufacturer's wiring diagram and by a licensed electrician.
Where is a propeller bulb used?
A propeller bulb is a high-lumen LED bulb that fits an E27 lamp holder, with its LEDs placed on a blade-shaped body. It is used in places such as garages, warehouses, workshops and shops where strong light is wanted from a single lamp holder point. Because its body is much larger than a standard bulb, it may not fit in enclosed or narrow luminaires; check the dimensions in the product data.