What size barrel is the APX A1 carry?

I'm curious about the specifications of the APX A1 carry pistol. Specifically, what size barrel does it have? As a firearms enthusiast, I understand that the barrel size can significantly impact the pistol's performance, accuracy, and even its feel in the hand. Can you please elaborate on the barrel size of the APX A1 carry and any other relevant details that might be of interest to someone considering purchasing this pistol?