The ATK GT250R uses an H1 bulb size for high beam headlight operation and an H3 bulb size for low beam headlight operation. The replacement chart covers vehicle production spanning 2011 to 2014 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.
The ATK GT250R uses the H1 bulb for high beam headlights across the 2011-2014 model years.
The H1 is a single-filament halogen bulb operating at 12V and 55W, fitted with a P14.5s base and produced under the ECE standard, with approval also extended to the US and Japan.
The ATK GT250R uses the H3 bulb for low beam headlights across the same 2011-2014 model year range.
The H3 is a single-filament halogen bulb operating at 12V and 55W, fitted with a PK22s base and likewise produced under the ECE standard, with approval in the US and Japan.
Although the H1 and H3 share identical voltage and wattage ratings, their base types differ. The P14.5s base of the H1 and the PK22s base of the H3 are not interchangeable, meaning the two bulbs cannot substitute for one another despite their electrical similarities.
The ECE designation indicates that both bulb types conform to the United Nations Economic Commission for Europe lighting regulations, a widely adopted international standard governing bulb construction and output.