The Volvo C30 side marker utilizes a 12961 bulb size for the exterior lighting system on the vehicle. Data for the specific component covers the range from 2008 through 2013.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Volvo C30 front side marker position uses the 12961 bulb across all model years covered in the specifications, spanning 2008-2013.
The 12961 is a Philips part number designating a T10 miniature wedge bulb with a W2.1x9.5d base, rated at 12V and 5W.
The T10 wedge form factor is a small, tapering plastic base that friction-fits directly into a socket without any rotation or locking mechanism.
The rear side marker position on the Volvo C30 uses a different bulb type entirely, the P21/4W, for the 2008-2009 model years.
The P21/4W is an ECE-standard dual-filament bulb rated at 12V with two wattage outputs, 21W and 4W, served through a BAZ15d bayonet base.
The BAZ15d base is an offset bayonet fitting, meaning its two pins are positioned at different heights to prevent incorrect installation of the bulb.
Because the front marker uses a wedge-base T10 and the rear marker uses a bayonet-base P21/4W, the two bulb types are not interchangeable with each other.
The P21/4W designation follows ECE (Economic Commission for Europe) naming conventions, which are standard across European and many international vehicle markets.