Optics ready plates for Glock 31

The Glock 31 MOS is the full-size .357 Sig Glock with the Modular Optic System. The factory cut accepts standard plates — the same geometry as the G17 MOS.

Running a red dot low on the slide means you find the dot quickly and track it through the shot with both eyes open, rather than aligning two iron sights under time pressure. The plate is what turns the Glock 31 into an optic-ready gun: it fills the mounting interface and presents the exact footprint your red dot needs, so the optic sits flat and stays put under recoil.

Two dimensions have to line up — the cut or rail on the Glock 31 and the footprint of the optic you intend to run. A few plates include an integrated rear sight to preserve a co-witness backup. Check both against your setup on the individual product page before ordering.