Chambered in .9mm, this barrel is meant to fit with the P320 Compact model. The barrel can be replaced easily and conveniently by simply ensuring the firearm is unloaded, removing the slide from the receiver and grip module, and sliding out the existing barrel.
Sig Sauer BBLMODC9 P320Fits Sig P320 9mm Luger 3.90″ Black Nitride Steel