[4] It is offered with Tritium XRAY3 Day/Night Sights and two 10-round magazines; one flush fit and the other with an extended finger tab, and a stainless steel frame with polymer grip module.

It is primarily chambered in 9×19mm Parabellum and is rated for +P (higher pressure) ammunition while utilizing offset double-stack magazines.

The magazine is released by a triangular button on the grip located at the undercut trigger guard section.

[10] For Massachusetts Attorney General compliance requirements, a model with a manual safety and loaded chamber indicator is available.

Starting in late-2023, a California roster listed model with loaded chamber indicator, magazine disconnect, and manual safety was also released as the SIG 365-9-BXR3P-MS-CA.

[12] The grip encloses a stainless steel fire control unit (FCU) similar to that in the SIG Sauer P320.

[19] It utilizes the same fire control unit (FCU) as the P365, while having a larger grip module that accepts 12-round flush magazines, a flat trigger, and a longer slide and barrel.

[26] It also features a removable plate on the slide (allowing installation of a red dot sight) and ships with three 17-round magazines (where legal).

The first P365XL Spectre[d] was introduced in June 2021 featuring a distressed finish and an X-shaped cutout on top of the slide.

[34] In February 2022, the P365XL Spectre Comp was introduced with an integrated compensator; it also has a gold-colored barrel, but its flat trigger is not skeletonized.