I have no idea but will check tomorrow as the light is still at my old shop. If it does not fit yours then I doubt it will fit mine. Maybe AW's older blue cells will fit?
In my picture, that light is running on a newer AW protected 17670 cell with the black label still on it. Only had to peal the small silver label off. It is a little tight but tapping the tube lightly in my hand gets the cell out. Those protected cells can vary a little in diameter at the ends.
I actually tested that Mule head out last night in my new backyard and was totally impressed at how one XR-E driven at around 500ma can illuminate so much in the dark. The Mule was lighting up my whole neighbors house that has to be 150 + Feet away.