Sig Sauer P365 FCU | Gold Nitride | 8900164

The Sig Sauer P365 Custom Works Fire Control Unit (FCU) converts the P365 micro-compact platform into a highly configurable chassis component. This listing is for the FCU only; it provides an exclusive finish and a flat-face trigger designed for refined trigger feel and repeatable operation. The FCU is compatible with Sig P365 parts and common P365 modules, allowing users to tailor the pistol for everyday carry or competition carry setups.

Product Specifications

• The manufacturer is Sig Sauer.
• The model is listed as the Custom Works Fire Control Unit (P365 FCU).
• The frame finish is Gold Nitride.
• The trigger finish/coating is Gold/Titanium Nitride (as described by the manufacturer).
• The trigger type is a Flat Face skeletonized blade.
• The product type is classified as Striker Fired.
• The action classification is Semi-Auto.
• The safety configuration is listed as No Thumb Safety.
• The FCU includes a custom FCU serial number.
• The unit is compatible with Sig P365 parts and P365-compatible modules.
• The series is Custom Works Fire Control Unit.
• The ATF type is recorded as FRAME and the ATF model as P365.
• The ATF manufacturer is SIG SAUER.
• The manufacturer part number is 8900164.
• UPC: 798681659548.

This FCU is aimed at shooters who want a high-quality core component for customizing a P365 platform. Its distinctive Gold Nitride appearance and flat-face trigger make it well suited to daily carry builds where a refined trigger pull and tailored ergonomics matter, and it also serves as a solid upgrade option for competition carry classes that use micro-compact pistols. The FCU-only format allows experienced builders and gunsmiths to integrate the unit into existing P365 frames and accessory ecosystems with maximum flexibility.