Three options listed in the installation manual, page 6-11:
Option 1: Stack Cutout (installed from front of panel): 6.32" wide
Option 2: Radio Cutout (Installed from front of panel): 6.32" wide x 2.03" tall
Option 3: Radio Cutout (Installed from back of panel): 6.25" wide x 1.98" tall
If you'd like to email me directly I can pass along the installation manual.