The Duo is a dual optical mounting system that locates a T1/T2 optic forward and above the user’s Primary Arms 5X MicroPrism, providing the same “2-hole” cantilever distance (1.25”) and 1.54” optical centerline that Primary Arms gives with one of their included spacers. The red dot height will vary, but is nominally 2.8” with low-cut T1-pattern dots and clones.

Compatible with the included mount and a number of other third-party bases, the Duo maintains relative positioning between the prism and red dot (or 1X T1 footprint prism sight, if opted for) across bases.

Machined from 7075-T6 and protected by the standard type III anodize coating, this spacer both upgrades the stability of the prism and saves rail space in mounting a forward dot, for which these incredible compact optics have no native mounting base.

The included PETG-CF shade prevents glint from the prisms objective lens and protects the same from impact. 5X shades press onto the 5X’s optical bell, whereas the 3X shade presses over the rear cantilever deck.

#5-40 holes on the front face allow sunshade mounting. These are in development.

The spacer itself weighs 4 oz and includes the necessary fasteners for both the OEM picatinny clamp and a set of .125” longer screws in case use of an ADM or similarly thicker mount is desired.