This SIG SAUER P320 Caliber X-Change Kit only requires your P320 FCU from any size P320, just drop your FCU into the kit, assemble, and you're good to go.
The SIG SAUER P320 Caliber X-Change Kit allows you set up your P320 Compact in .40 S&W and comes with a barrel/slide assembly, grip module, and 10 round magazine. This kit is not compatible with manual safety models of the Sig Sauer P320.
The slide included with the SIG SAUER P320 Caliber X-Change Kit will work. However, the grip module would not be compatible.
The SIG SAUER P320 Caliber X-Change Kit is a full kit made to convert your P320. All you need is the FCU from your existing P320 for this kit to work.
The SIG SAUER P320 Caliber X-Change Kit CALX-320C-40-BSS has the large grip module.
The barrel length should be 3.9".
If you want the unit that includes the magazine, you need model SD9-CNC-CALX-CALX-320SC-9-BSS-10-10RD and that only comes with a 10 round magazine.
These come directly from Sig Sauer and will be the most updated version of the kit that is available.
These are all coming new directly from Sig, they are the new version that fits the upgraded pistols.
No, night sights are not included.