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What red dots fit the Shadow Systems Foundation Series?

Page last updated October 1, 2026. Data compiled September 2026 by Andrew Terrebonne.

59 of the 77 optics tracked here mount to this slide, and 58 of those need no adapter plate. This slide uses Shadow Systems multi-optic cut (MR920, DR920, XR920).

No plate neededPlate neededDoesn’t fit

Mount systemShadow Systems multi-optic cut (MR920, DR920, XR920)

Optics that fit59 of 77

No plate needed58

Plate to buy1

Plate to slideper plate instructions

Optic to slide10–20 in-lb

New to red dots? What footprint, plate, co-witness and the rest mean

Screw thread trapShadow Systems does not state the slide's thread. It supplies its own screws in an optic kit taped inside the lid of the pistol box, so use those, not the ones in the optic's box.

Cheapest ways to mount it

Cheapest overall, and with no plate$60–150Cyelee Cat / Wolfdirect — no adapterBuild sheet

Cheapest enclosed emitter$300–450Holosun EPS-COREdirect — no adapterBuild sheet

Same slide cutThe Shadow Systems MR920, Shadow Systems DR920 / DR920P, Shadow Systems XR920 / XR920P and Shadow Systems MR920 Elite / Combat share this slide's optic cut (Shadow Systems multi-optic cut (MR920, DR920, XR920)), so the optics, plates and screws below are the same for all of them. What differs between the models is under "On this model", where there is anything.

How this slide mounts an opticNo plates: the slide is cut so that optics from several footprints bolt straight on, held by Shadow's own screws from an optic kit in the pistol box. Shadow's optic-fit table names the Trijicon RMR and SRO, the Holosun 407C, 507C, 508T, 407K, 507K, EPS and EPS Carry, the Leupold DeltaPoint Pro, the EOTech EFLX, the Shield RMSc, the Vortex Viper and a few Swampfox and TruGlo models, and says any optic that fits the recess and lines up with a set of holes can likely be mounted. Shadow's page says the SIG Romeo 1 Pro, left off the table, can take Spacer B sanded to fit its rear. A polymer spacer, sold for most of them, is optional: Shadow says it is not needed to keep the optic on. The rear sight blocks the windage and elevation locking screws on a Viper or Trutec until it is drifted out. C&H Precision sells adapter plates for the optics the cut does not take directly, such as the Holosun 509T.

Every optic, and how it mounts

Item	Footprint	How it mounts	Cost to mount
Direct — 18
ADE Delta Pro Build sheet	Trijicon RMR	direct — no adapter	$60–150
Ameriglo Haven Build sheet	Trijicon RMR	direct — no adapter	$150–300
C&H Precision Comp Build sheet	Trijicon RMR	direct — no adapter	$300–450
Cyelee Cat / Wolf Build sheet	Trijicon RMR	direct — no adapter	$60–150
Holosun 407C X2 Build sheet	Trijicon RMR	direct — no adapter	$150–300
Holosun 407COMP Build sheet	Trijicon RMR	direct — no adapter	$300–450
Holosun 507-Promax Build sheet	Trijicon RMR	direct — no adapter	$300–450
Holosun 507C X2 Build sheet	Trijicon RMR	direct — no adapter	$300–450
Holosun 507C X3 / 407C X3 Build sheet	Trijicon RMR	direct — no adapter	$300–450
Holosun 507COMP Build sheet	Trijicon RMR	direct — no adapter	$300–450
Holosun 508T X2 Build sheet	Trijicon RMR	direct — no adapter	$300–450
Meprolight MPO-DF Build sheet	Trijicon RMR	direct — no adapter	$300–450
Riton 3 TACTIX PRD Build sheet	Trijicon RMR	direct — no adapter	$150–300
Swampfox Justice II Build sheet	Trijicon RMR	direct — no adapter	$150–300
Swampfox Liberty II Build sheet	Trijicon RMR	direct — no adapter	$150–300
Trijicon RMR HD Build sheet	Trijicon RMR	direct — no adapter	$650–900
Trijicon RMR Type 2 Build sheet	Trijicon RMR	direct — no adapter	$450–650
Trijicon SRO Build sheet	Trijicon RMR	direct — no adapter	$450–650
Direct (cross-fit) — 40
Burris FastFire 3 Build sheet	Docter / Noblex	direct — no adapter	$150–300
Burris FastFire 4 Build sheet	Docter / Noblex	direct — no adapter	$150–300
Bushnell RXS-100 Build sheet	Leupold DeltaPoint Pro	direct — no adapter	$150–300
Crimson Trace CTS-1550 Build sheet	Shield RMSc	direct — no adapter	$150–300
EOTECH EFLX Mini Build sheet	Leupold DeltaPoint Pro	direct — no adapter	$300–450
Holosun 407K X2 Build sheet	Holosun K	direct — no adapter	$150–300
Holosun 507K X2 Build sheet	Holosun K	direct — no adapter	$300–450
Holosun 507K X3 / 407K X3 Build sheet	Holosun K	direct — no adapter	$300–450
Holosun EPS EnclosedBuild sheet	Holosun K	direct — no adapter	$300–450
Holosun EPS Carry EnclosedBuild sheet	Holosun K	direct — no adapter	$300–450
Holosun EPS-CORE EnclosedBuild sheet	Shield RMSc	direct — no adapter	$300–450
Holosun SCS Carry EnclosedBuild sheet	Holosun K	direct — no adapter	$300–450
JP Enterprises JPoint Build sheet	Shield RMSc	direct — no adapter	$150–300
Leapers UTG OP3 Micro Build sheet	Docter / Noblex	direct — no adapter	$60–150
Leupold DeltaPoint Pro Build sheet	Leupold DeltaPoint Pro	direct — no adapter	$300–450
Meopta MeoSight IV Build sheet	Docter / Noblex	direct — no adapter	$150–300
Noblex Sight III / Docter Sight C Build sheet	Docter / Noblex	direct — no adapter	$300–450
Olight Osight K Build sheet	Holosun K	direct — no adapter	$60–150
Olight Osight S Build sheet	Shield RMSc	direct — no adapter	$60–150
Primary Arms Classic 21 mm Micro Build sheet	Shield RMSc	direct — no adapter	$60–150
Riton 3 TACTIX MPRD 2 Build sheet	Shield RMSc	direct — no adapter	$150–300
Shield Sights RMS2 Build sheet	Shield RMSc	direct — no adapter	$150–300
Shield Sights RMSc Build sheet	Shield RMSc	direct — no adapter	$150–300
SIG Sauer ROMEO-X Compact Build sheet	Shield RMSc	direct — no adapter	$150–300
SIG Sauer ROMEO-X Pro Build sheet	Leupold DeltaPoint Pro	direct — no adapter	$300–450
SIG Sauer ROMEO1PRO Build sheet	SIG Romeo1Pro	direct — no adapter	$300–450
SIG Sauer ROMEOZero Build sheet	Shield RMSc	direct — no adapter	$60–150
SIG Sauer ROMEOZero Elite Build sheet	Shield RMSc	direct — no adapter	$150–300
Sightmark Mini Shot A-Spec Build sheet	Docter / Noblex	direct — no adapter	$60–150
Springfield Armory Hex Dragonfly Build sheet	Docter / Noblex	direct — no adapter	$150–300
Springfield Armory Hex Wasp Build sheet	Shield RMSc	direct — no adapter	$150–300
Swampfox Sentinel II Build sheet	Shield RMSc	direct — no adapter	$60–150
Trijicon RCR EnclosedBuild sheet	Trijicon RCR	direct — no adapter	$650–900
Viridian RFX35 Build sheet	Shield RMSc	direct — no adapter	$60–150
Vortex Defender-CCW Build sheet	Shield RMSc	direct — no adapter	$150–300
Vortex Defender-SL Build sheet	Leupold DeltaPoint Pro	direct — no adapter	$150–300
Vortex Defender-ST Build sheet	Leupold DeltaPoint Pro	direct — no adapter	$300–450
Vortex Defender-XL Build sheet	Leupold DeltaPoint Pro	direct — no adapter	$300–450
Vortex Venom Build sheet	Docter / Noblex	direct — no adapter	$150–300
Vortex Viper Build sheet	Docter / Noblex	direct — no adapter	$150–300
Plate to buy — 1
Holosun 509T EnclosedBuild sheet	Holosun 509T	plate: MR920 / XR920 → Holosun 509T (steel)	$510–745
No fit — 18
ADE NUWAcc Pro	Trijicon RMRcc	no known route	—
Aimpoint ACRO C-2 Enclosed	Aimpoint ACRO	no known route	—
Aimpoint ACRO P-1 Enclosed	Aimpoint ACRO	no known route	—
Aimpoint ACRO P-2 Enclosed	Aimpoint ACRO	no known route	—
Aimpoint COA Enclosed	Aimpoint COA / A-Cut	no known route	—
Aimpoint Micro T-2 Enclosed	Aimpoint Micro	no known route	—
C-More RTS2	C-More RTS2 / STS2	no known route	—
C-More STS2	C-More RTS2 / STS2	no known route	—
Holosun SCS 320 Enclosed	Holosun SCS (320)	no known route	—
Holosun SCS MOS Enclosed	Holosun SCS (MOS)	no known route	—
Lucid Optics E7 Enclosed	Aimpoint ACRO	no known route	—
SIG Sauer ROMEO-X Enclosed	SIG-LOC	no known route	—
SIG Sauer ROMEO-X SIG-LOC Compact Enclosed	SIG-LOC	no known route	—
SIG Sauer ROMEO-X SIG-LOC Pro Enclosed	SIG-LOC PRO	no known route	—
SIG Sauer ROMEO2 Enclosed	SIG Romeo2	no known route	—
Steiner MPS Enclosed	Aimpoint ACRO	no known route	—
Trijicon RMRcc	Trijicon RMRcc	no known route	—
Viridian RFX45 Enclosed	Aimpoint ACRO	no known route	—

Adapter plates for the Shadow Systems Foundation Series

Plate	Gives you	Source	Price
MR920 / XR920 → Trijicon RMR / SRO / RCR / Holosun CThe RMR and Holosun 407C / 507C / 508T also mount directly on this cut.	Trijicon RMR Trijicon RCR	C&H Precision ↗	$25–60
MR920 / XR920 → Leupold DeltaPoint ProThe DeltaPoint Pro also mounts directly on this cut.	Leupold DeltaPoint Pro	C&H Precision ↗	$25–60
MR920 / XR920 → Holosun K / EPSThe Holosun 507K also mounts directly on this cut.	Holosun K	C&H Precision ↗	$25–60
MR920 / XR920 → Holosun EPS / EPS CarryShadow sells an EPS / K spacer kit for mounting these directly.	Holosun K	C&H Precision ↗	$25–60
MR920 / XR920 → Holosun 509T (steel)	Holosun 509T	C&H Precision ↗	$60–95

Plate

Gives you

Source

Price

MR920 / XR920 → Trijicon RMR / SRO / RCR / Holosun CThe RMR and Holosun 407C / 507C / 508T also mount directly on this cut.

Trijicon RMR
Trijicon RCR

C&H Precision ↗

$25–60

MR920 / XR920 → Leupold DeltaPoint ProThe DeltaPoint Pro also mounts directly on this cut.

Leupold DeltaPoint Pro

C&H Precision ↗

$25–60

MR920 / XR920 → Holosun K / EPSThe Holosun 507K also mounts directly on this cut.

Holosun K

C&H Precision ↗

$25–60

MR920 / XR920 → Holosun EPS / EPS CarryShadow sells an EPS / K spacer kit for mounting these directly.

Holosun K

C&H Precision ↗

$25–60

MR920 / XR920 → Holosun 509T (steel)

Holosun 509T

C&H Precision ↗

$60–95

GuidesShield RMSc vs Holosun K: which optic fits which cut · Suppressor-height sights: will your irons co-witness? · Installing a red dot: what the makers say

Check a specific pairing

Open the fit checker with this pistol selected, or click any "how it mounts" cell above for that pairing's verdict and build sheet.

Deciding between a few? Compare 3 popular optics on this slide side by side: window, weight, emitter, cost to mount and co-witness.

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