Sig Sauer P320 Custom Works Fire Control Unit, Black (8900161)

From the very beginning, the SIG SAUER P320 was engineered with adaptability in mind, and the SIG SAUER P320 Fire Control Unit (FCU) is the heart of that modular system. Designed to give shooters unmatched customization potential, this striker-fired FCU allows you to build a pistol tailored precisely to your needs, whether for duty, competition, or personal use.

This exclusive FCU features a Titanium Nitride–coated frame paired with a skeletonized flat blade trigger finished in Titanium Nitride for enhanced durability, a smooth trigger pull, and a refined feel. Compatible with 9mm, .40 S&W, and .357 SIG P320 platforms, it seamlessly integrates with all post-upgrade P320 grip modules, slides, barrels, magazines, and optics-ready configurations.

The modular design of the P320 system allows this Fire Control Unit to serve as the serialized core of your firearm, making it easy to swap components and reconfigure your setup without sacrificing reliability or performance. With no external thumb safety and a clean, streamlined profile, the FCU delivers consistent operation and modern ergonomics.

Ideal for builders and enthusiasts alike, the SIG SAUER P320 Fire Control Unit offers premium materials, proven engineering, and endless configuration possibilities—making it the perfect foundation for a truly personalized P320 pistol.