Yes, it has the thinner black ramp front sight of the CS-1, not to mention the frame stamp.
There are several good threads about these here. By report the 3" models were carried more by field officers and the 4" (like this one) by dog handlers. Enjoy!
Actually the 3 inch model was issued to Special Agent, and Air/Marine Division officers. The 4 inch was issued to the uniformed Inspectors and Dog Handlers.
