I have the Automaxx version, and the span from the pad to the tip of the round pocket hole end is 4-5/16 inches.
Ken would be correct in the actual opening size from the pad to the tip. However, since the tip will be in the pocket hole itself it will give you the 5" reach our website states. However, with the project you are working with, it will not open enough to clamp the pieces in your project. If you have any other questions please let us know.