Match the cap, fit the bulb
Choosing the right light bulb cap is essential for compatibility and performance. Our extensive range includes popular fittings such as Bayonet (B22), Edison Screw (E27, E14), and specialist caps for every lighting application.
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Visual reference for every common cap — click through to bulbs that fit.
Cap fittings explained
Bayonet, Edison Screw, twist-and-lock or push-fit — here's how to identify the cap on the bulb you're replacing.
GU10 — Twist & Lock
Two stubby pins, 10mm apart, that twist and lock into the holder. Mains-voltage (240V) — no transformer needed. The standard fitting for almost all modern UK downlights and spotlights.
Shop GU10 Bulbs B22 / BCBayonet Cap (B22)
The classic British fitting — two side pins that push in and twist a quarter-turn to lock. Found on traditional pendants, lamps, and most older ceiling roses. Sometimes called BC.
Shop B22 Bulbs E27 / ESEdison Screw (E27)
The continental and increasingly common UK fitting — a 27mm threaded base that screws in like a jar lid. Standard for filament-style bulbs, designer pendants and most imported fittings.
Shop E27 Bulbs E14 / SESSmall Edison Screw (E14)
A smaller, 14mm screw version of the E27 — common on candle bulbs, chandeliers, fridge lamps and bedside table lamps. Often called SES (Small Edison Screw).
Shop E14 Bulbs GU5.3 / MR16GU5.3 — Push-Fit Pins
Two thin push-fit pins, 5.3mm apart. Almost always low-voltage (12V), so requires a transformer or LED driver upstream. Common in older recessed spotlights and accent lighting.
Shop GU5.3 / MR16 G9G9 — Mains Capsule
A compact loop-pin cap running on 240V — no transformer. Very common in modern decorative pendants, wall lights and Italian/European-styled fittings where a small bright source is needed.
Shop G9 Bulbs G4G4 — Low-Voltage Capsule
Tiny 12V capsule with two close-set pins. Used in delicate decorative fittings, display cabinets, and under-cabinet lights. Always needs a 12V driver or transformer.
Shop G4 Bulbs R7sR7s — Linear Double-Ended
A double-ended fitting — the linear bulb pushes between two spring-loaded contacts. Common in floodlights, uplighters and patio heaters. Measurement matters: lengths range from 78mm to 254mm.
Shop R7s Bulbs G53 / AR111G53 / AR111
The cap for AR111 (111mm aluminised reflector) lamps — used in larger architectural downlights and museum-style display lighting. Excellent beam control, available in narrow, medium and wide flood angles.
Shop AR111 BulbsNot sure which cap you have?
Send us a photo of your existing bulb (or the empty fitting) and we'll identify the cap and recommend the right replacement.