If you have a shorter slide version of the (P365, standard P365, P365X, P365 SAS, or a short slide swapped to an XL grip module), you should use the shorter Tactical Application Rail TAR or Pro Ledge Tactical Application Rail PL-TAR, except in one situation, you are using a short slide with a compensator. In that case the XL versions of the Tactical Application Rails are recommended XLTAR, PL-XLTAR, as the end of the rail extends closer to the end of the comp, and allows the use of larger/longer lights, lasers, or other picatinny 1913 rail mounted accessories.
Examples of a PMM Compensator, and XL length rail can be seen in the pictures on the PL-XLTAR product page. For a summary, please consult the 'Choose Your Rail Length' chart on the PL-XLTAR page. Please note that the XL length Rails should not be used if the compensator is removed from the shorter slide, as the gasses discharged from the end of the barrell will affect it's integrity, and voids the warranty. It also looks pretty silly.
Both the short versions of the rails, TAR and PL-TAR, are the same length. Both the XL version of the rails are the same length XLTAR. PL-XLTAR.
If you are using the XL length slide (P365XL, P365XL Spectre Comp), use the XL length rails XLTAR, PL-XLTAR.
**Short slide rails**
TAR product page
https://tactical.dev/collections/p365x-products/products/sig-p365-front-rail-conversion
PL-TAR product page
https://tactical.dev/collections/p365x-products/products/pro-ledge-tactical-application-rail-for-p365
**Longer XL slide, or short slide with a compensator rails.**
XLTAR
https://tactical.dev/collections/p365xl-products/products/extended-tactical-application-rail-for-p365-xl
PL-XLTAR
https://tactical.dev/collections/p365xl-products/products/p365-pro-ledge
The addition of a picatinny rail is not needed for the Xmacro grip module, but we have a Pro Ledge TAR for adding the thumb ledge for an xMacro, which various lights can be added to the included rail below.
https://tactical.dev/collections/p365-x-macro/products/pro-ledge-tar-for-sig-p365-xmacro
We also have a Pro Ledge thumb ledge specifically for the Streamlight TLR7 Sub 1913, or TLR8 Sub 1913. This only adds a thumb ledge by substituting one of the sides of the light's clamps. This works on various picatinny rail grip modules, see page for details.
https://tactical.dev/collections/p365-x-macro/products/proledge-for-sig-p365-x-macro