Ski-Doo Summit 1000 Highmark Brake Bulb Size

The Ski-Doo Summit 1000 Highmark uses 921 and 1157 bulb sizes for brake applications. The replacement chart covers 2005 to 2007 model years with corresponding bulb size specifications.

The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.

Bulb Size by Year Range

Years	Bulb Size
2007	921
2005-2006	1157

Bulb Specifications

Description	Bulb Size
ANSI standard (US & Canada). Wedge bulb (T15). 12V, 16W.	921
ANSI standard (US & Canada). Dual-filament bulb with BAY15d bayonet base. 12V, 21W/5W.	1157

Other Locations

Additional Notes

The 1157 bulb is a dual-filament type rated at 12V with a 21W/5W output, using a BAY15d bayonet base. Its two filaments serve separate functions within a single housing, which is a common configuration for brake and tail light applications that require different brightness levels.
The 921 bulb is a single-filament wedge type in a T15 form factor, rated at 12V and 16W. Its wedge base differs structurally from the bayonet base of the 1157, making the two bulbs physically incompatible with each other despite sharing the same 12V operating voltage.
Both the 921 and 1157 are designated under the ANSI standard applicable in the United States and Canada, meaning their electrical and physical specifications conform to a recognized North American classification system.
The Ski-Doo Summit 1000 Highmark uses the 1157 bulb for the 2005-2006 model years and transitions to the 921 for the 2007 model year. These two bulb types are not interchangeable due to differences in base type, filament count, and wattage.