Glock 43X MOS red dot options: what mounts directly and what needs a plate
The Glock 43X MOS Slimline cut is the Shield RMSc footprint. See which optics mount with no plate, which Holosun K optics need one, and what is in stock now.
Quick answer
- Footprint: the Glock 43X MOS slide is cut for the Shield RMSc pattern, with four recoil bosses. RMSc pattern optics mount with no plate. Holosun K series (407K, 507K, EPS Carry) need a thin plate unless the item number ends in MOSK, the two boss cut Glock began shipping in late 2025. Full size optics like the RMR do not fit.
- 77 red dots mount directly to the Glock 43X MOS with no plate, from the GunPartPicker catalog. 13 more mount with a plate across 1 footprint.
Source: GunPartPicker catalog and build data, prices checked October 13, 2026.
Glock 43X MOS red dot options: what fits
The Slimline MOS cut is the Shield RMSc pattern, four recoil bosses. RMSc optics mount directly. Holosun K series need a thin plate, unless the item number ends in MOSK, the two boss cut Glock began shipping in late 2025. Full size optics do not fit.
Narrow to the pattern on the bottom of the optic you already own.
Mount directly
77
38 in stock
Mount with a plate
13
1 footprints
Slide cut
Slimline MOS
Slimline, 9mm
Direct footprints
Shield RMSc
no plate needed
Red dots that fit the Slimline MOS cut without a plate
The Slimline MOS cut is the RMSc pattern itself, so these bolt straight to the slide.
Ranked by what builders add most, in stock first. One listing per model.
Holosun K footprint red dots for Glock MOS, plate required
Holosun 407K, 507K, EPS Carry and SCS Carry. Steel plates for this footprint are listed under the optics.
Optics
Ranked by what builders add most, in stock first. One listing per model.
Plates for Holosun K
Ranked by what builders add most, in stock first. One listing per model.
Glock 43X MOS pistols in stock
Factory MOS pistols at this model, ready for a plate and an optic out of the box.
Ranked by what builders add most, in stock first. One listing per model.
How Glock MOS plates and optic footprints work
The thing that determines fit is the footprint: the pattern of screw holes and recoil bosses on the bottom of the optic. A handful of patterns cover almost every pistol dot sold. Trijicon's RMR is the most copied full size pattern. Shield's RMSc, which Holosun's K series shares, is the compact pattern. Aimpoint ACRO, Leupold DeltaPoint Pro and Holosun's 509T each have their own.
A factory MOS slide does not carry any of those patterns. It carries a pocket for a plate, and the plate carries the footprint. Glock's own plates are thin steel and cover four patterns; aftermarket plates cover the rest, and most are thicker, with longer screws and recoil bosses. The G43X MOS and G48 MOS are the exception: their Slimline cut is the RMSc pattern itself, so RMSc optics mount directly. Holosun K optics take a thin plate unless the slide is a newer MOSK, and full size optics do not fit at all.
Aftermarket slides skip the plate. They are milled for one footprint, usually RMR, and the optic bolts straight to the steel. That is lower, more rigid and one fewer set of screws to come loose, at the cost of being locked to one pattern.
Glock optic footprint chart: RMR, RMSc, Docter, ACRO, DeltaPoint Pro
| Footprint | Size | Optics on it | On a MOS slide |
|---|---|---|---|
| Trijicon RMR | full | Trijicon RMR, SRO and RCR, Holosun 407C, 507C, 508T and 507COMP, Holosun EPS (with its adapter), Swampfox Liberty and Justice | Plate |
| Shield RMSc | compact | Shield RMSc and RMS, Sig RomeoZero, Swampfox Sentinel, Vortex Defender-CCW | Slimline: direct. Full size: plate |
| Holosun K | compact | Holosun 407K, 507K, EPS Carry and SCS Carry | Slimline: plate (direct on MOSK). Full size: plate |
| Docter / Noblex | full | Vortex Venom and Viper, Burris FastFire 2, 3 and 4, Docter, Noblex, Meopta MeoSight | Plate |
| Aimpoint ACRO | enclosed | Aimpoint ACRO P-1 and P-2, Steiner MPS | Plate |
| Leupold DeltaPoint Pro | full | Leupold DeltaPoint Pro, Sig Romeo-X Pro, EOTech EFLX, Vortex Defender-ST and XL, Bushnell RXS-250 | Plate |
| Holosun 509T | enclosed | Holosun 509T and 509X | Plate |
| Trijicon RMRcc | compact | Trijicon RMRcc | Plate |
| Sig Romeo1 Pro | full | Sig Romeo1 Pro | Plate |
Frequently Asked Questions
What footprint is Glock MOS?
MOS is not a footprint. It is a plate system. The slide takes a plate, and the plate carries the optic footprint. The Slimline MOS cut on the G43X MOS and G48 MOS is different: it is the Shield RMSc pattern cut straight into the slide.
Which MOS plate fits a Holosun 507C?
The 507C is on the Trijicon RMR footprint, so it uses Glock's plate 02 (06 on a 10mm, .45 or Gen5 .40) or any aftermarket RMR plate. The same goes for the 407C, 508T, Trijicon SRO and RCR.
Can I mount a red dot on a Glock that is not MOS?
Yes: have the slide milled for the footprint you want, buy an optic cut aftermarket slide, or use a dovetail mount that replaces the rear sight. Milling and a new slide are the solid options; dovetail mounts sit high and lose the rear sight.
Do I need new iron sights with a red dot?
Usually. Standard height Glock sights sit below most optic windows. Suppressor height sights give a lower third co-witness through the dot, and they are the backup if the optic dies.
Are the factory MOS plates good enough?
For a range gun, yes. The plates in the box are thin steel with short screws, torqued to about 13 in-lb per Glock. For a carry or competition gun a thicker machined plate with recoil bosses and longer screw engagement is the upgrade, and the screws that come with the plate are the ones to use, with threadlocker.
Which red dots fit a Glock 43X MOS or 48 MOS?
Shield RMSc pattern optics mount directly: Shield RMSc, Sig RomeoZero, Swampfox Sentinel and Vortex Defender-CCW. Holosun 407K, 507K and EPS Carry need a thin plate on the original four boss cut; slides whose item number ends in MOSK take them directly. Full size optics do not fit the Slimline cut.
Does the Holosun SCS need a plate?
No. The SCS-MOS is built to mount directly to a full size or compact Glock MOS slide with no plate, which also keeps it lower than any plated optic.
Cite this tool: GunPartPicker, “Glock 43X MOS red dot options: what mounts directly and what needs a plate”, https://gunpartpicker.net/tools/glock-red-dot-fit/glock-43x-mos. Data from the GunPartPicker catalog and real community builds, prices checked October 13, 2026. Free to cite with attribution.
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