Fire Control Unit (FCU)

The FCU is the component (frame) that houses a majority of the key functional parts of some handguns; including parts such as the trigger, sear, and slide catch lever; and is the serialized part of the firearm. With the SIG SAUER P320 or P365 modular handguns, the FCU can be easily removed from the grip module and swapped out with a variety of grips, barrels, and slides to create a firearm suited specifically to the shooter and intended use of the handgun.