Use this corner box on overhangs up to 8" Gable x 12" Eave @ 4/12 pitch or less.
If Gable is more than 8" or Eave more than 12" or if pitch is more than 4/12, use TCBM.
On overhangs up to 8" Gable x 12" Eave but pitch is more than 4/12 use TCBM.