Ski-Doo Summit Sport 600 Carb Brake Bulb Size

Additional Notes

• The P21/5W is the brake bulb used across all listed model years of the Ski-Doo Summit Sport 600 Carb, spanning 2012-2019.
• The P21/5W is a dual-filament bulb, meaning it contains two separate filaments within a single glass envelope. The higher-output filament operates at 21 watts and the lower at 5 watts, allowing one bulb to serve both a steady illumination function and a brighter signalling function.
• The P21/5W operates on a 12-volt electrical system, which is standard for powersport applications.
• The bulb uses a BAY15d bayonet base. The BAY15d designation indicates an offset double-contact base, where the two pins are positioned at different heights. This offset is a deliberate anti-misinstallation feature that prevents the bulb from being seated in the wrong orientation, which would reverse the two filaments.
• The P21/5W conforms to ECE (Economic Commission for Europe) standards, a regulatory framework recognized across Europe and numerous other markets worldwide.
• Because the BAY15d base uses offset pins, it is not interchangeable with the BA15d base, which has pins at equal heights. Substituting a BA15d bulb in a BAY15d socket is not possible without forcing the fitment, and doing so would result in incorrect filament assignment.
• The P21/5W should not be confused with the P21W, which is a single-filament bulb sharing a similar appearance but lacking the secondary 5-watt filament and using a BA15s single-contact base rather than the BAY15d dual-contact base.