If it's got two coils then it's probably a CWA/CWI ballast.
If one coil is totally isolated from the other it's a CWI otherwise if there is wires or a cap going between the two it's a CWA, both run the lamp nicely and will handle more line voltage problems then a simple reactor ballast, so they like to use them in highbays where line voltage problems can exist because of other loads running and they might even be SCWI which will take a 45% line voltage drop before extinguishing the lamp..