The KTM 640 Duke II uses 5008 and 232 bulb sizes for front turn signal applications, with 232 and 5008 sizes specified for rear turn signal positions. A replacement chart documents bulb size specifications across the 1999 to 2006 production range.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The KTM 640 Duke II uses two distinct bulb types across its turn signal positions: the 5008 and the 232, both of which conform to ANSI standards recognized in the US and Canada.
The 5008 is a single-filament bulb with a BA15s bayonet base, operating at 12V. It is a lower wattage variant of the more widely known 1156 bulb.
The 232 is a festoon bulb with an SV8.5 base, rated at 12V and 3W. Festoon bulbs are cylindrical in form and seat at both ends rather than using a pin or bayonet base.
The BA15s bayonet base of the 5008 features a single contact pin, which distinguishes it from dual-pin bayonet variants and makes it non-interchangeable with those types.
The 5008 and 232 are not interchangeable with each other due to their fundamentally different base types, one using a bayonet mount and the other a festoon end-cap mount.
On the KTM 640 Duke II, the front turn signal position used the 5008 consistently across the 2000-2006 model years, while the 1999 model year used the 232 in that same position.
The rear turn signal position shows variation across model years, with the 232 appearing in 2000, 2004, and 2006, and the 5008 appearing in 1999, 2001-2003, and 2005.
Because the rear turn signal bulb type differs between certain adjacent model years, such as between 2004 and 2005, substituting a bulb from a different year's specification without confirming the base type would result in an incompatible fitment.