This Sig Sauer P320 lower parts kit contains all the parts needed to complete a Sig P320 fire control unit (FCU). It ships with a flat-faced trigger, trigger bar, sear and sear housing, slide catch assembly, takedown lever, pins and springs. Parts are compatible with Sig P320 slides chambered in 9mm, 40 S&W and 357 SIG. All parts necessary to complete a Sig FCU or 80% MUP. Includes: Trigger stop pin Slide catch lever pin Safety lever pin Sear pivot pin Split coil pin Slide catch lever spring post Take down safety lever Safety lever Slide catch Sear O-ring Take down lever Slide catch assembly Spring, slide catch lever Spring, sear (2) Trigger bar spring Spring, takedown lever Flat Faced Trigger Trigger bar Sear housing Manual disconnector Lay out and check the parts against the list above before assembly and function-check the completed pistol, including trigger reset, before live fire.