Yea - Autozone will know?
I guess I could bring in my old one to judge the size I need. Otherwise, Autozone is worthless. They can't even tell me what rotors and pads I need half the time.
There were different sizes offered so it's best to measure. You can use a Vernier caliper, crescent wrench (tighten the jaws around the bar and then use a tape-measure to check the distance between the jaws) or use a soft-tape to measure circumference (then calculate diameter).