SIG Pro

The SIG Pro is a series of semi-automatic pistols developed by SIG Sauer in Exeter, New Hampshire. It became the first polymer-frame handgun from SIG Sauer and one of the first pistols to feature a built-in universal accessory rail and interchangeable grips. Offerings in the series are chambered in .40 S&W, .357 SIG, or 9×19mm Parabellum. , only the SP 2022 variant is still listed on the SIG Sauer website. The SIG Pro was marketed as a lightweight and compact alternative to the "legacy" SIG Sauer handguns in an increasingly competitive and budget-oriented law enforcement market.
Variants.
There have been two generations of SIG Pro offerings, with five total variants. The below are each hammer-fired semi-automatic pistols operating in double action / single action (DA/SA), with a decocker and without a manual safety, unless noted otherwise.
First generation.
These offerings feature a proprietary SIG accessory rail. It was originally developed as a .40 S&W–caliber service pistol and introduced in June 1998, followed shortly by a version in .357 SIG. About a year later, a 9×19mm Parabellum variant was introduced and entered production in response to demand for the type.
Second generation.
These offerings feature a Picatinny rail, and a trigger guard that is visibly different than the first generation variants. The design was selected in 2002 as a new service pistol for French police, intended to have a 20-year service life (until 2022), hence the model number.