Can't help specifically, but just get a full socket torx set + a t27 (usually not included in the set). That'll handle most of the fasteners on your ride, as well as many on most cars, trucks, around the house etc.
Just went out in the garage and checked... it's a T50. I picked up an inexpensive set of torx sockets at Harbor Freight...
I got my set at Kragen Auto Parts. Just make sure you set the bit all the way in the bolt and keep downward pressure on the socket wrench. They come out no problem.
Most damage is done using the incorrect size torx bit.
Went to the hardware store and bought a T50 and T55 figuring it had to be one of these. The winner was a T50. Probably the only time i will ever use it is removing the fender on this bike.