The Land Rover Discovery side marker utilizes a 12961 bulb size for illumination purposes within the lighting assembly. Data for the specific component covers the range from 1995 to 2004.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The Land Rover Discovery uses the 12961 for the front side marker position across the 1994-2004 model years.
The rear side marker position on the Land Rover Discovery uses the 12821 across the 1994-2002 model years.
Both the 12961 and 12821 are Philips part numbers belonging to the T10 miniature wedge bulb family, operating at 12V with a 5W output.
Both bulbs share the W2.1x9.5d wedge base, a standardized base type in which the bulb is held in place by friction rather than a locking mechanism, allowing tool-free removal.
Despite carrying different Philips part numbers, the 12961 and 12821 share identical electrical and physical specifications, both being T10 wedge bulbs rated at 12V and 5W with a W2.1x9.5d base.
The T10 designation refers to the bulb envelope width of 10mm, a common sizing standard used across a wide range of low-wattage automotive lighting applications.
At 5W, both bulbs fall within the low-wattage range typical of marker and clearance lighting, where output is intended for visibility rather than illumination.
The W2.1x9.5d base code describes a wedge-type base with a 2.1mm wire contact width and a 9.5mm insertion depth, which are the physical parameters governing socket compatibility.