Collection: Festoon Bulbs

The Festoon Bulb: Your Car's Dome Light

The festoon (or "shuttle") is an elongated cylindrical bulb with metal contacts at both ends. Its oblong shape allows it to fit into flat, rectangular housings—typical of automotive dome lights. It is the most common bulb for modern car interior lighting.

Festoon, C5W, SV8.5: Three Names for the Same Family

Three designations to know:

• "Festoon" — French commercial name, refers to the shape
• C5W / C10W — CEE electrical designation (C for festoon, 5W or 10W)
• SV8.5 — Technical designation for the base (8.5 mm contact)

On the packaging, you will often find "Festoon C5W SV8.5" — it's the same bulb, three parallel nomenclatures.

Which Festoon Size to Choose?

Length is the number one criterion — a festoon that is too short won't make contact, one that is too long won't fit. Three standard sizes:

• 31 mm — small dome lights, city cars (Renault Clio, Peugeot 208, Citroën C3)
• 36 mm — the most universal size (Renault Mégane, Peugeot 308, VW Golf, and most sedans)
• 42 mm — large dome lights, minivans, SUVs with large cabins

To measure: remove the old bulb and measure its total length (from contact to contact) with a ruler — or measure the length of the housing.

Upgrading Your Festoon Bulbs to LED

Clear advantages:

• Modern white light (4,000 to 6,500 K) vs. the yellow light of halogen
• No legal constraints for dome lights — all colors allowed indoors
• 10× longer lifespan
• Choose the shade: cool white (reading, handling), warm white (ambiance), blue/red (personalization)

See also our C5W (same bulb, different designation) and SV8.5 collections.