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What red dots fit the SIG Sauer P365X?

Page last updated . Data compiled September 2026 by Andrew Terrebonne.

22 of the 77 optics tracked here mount to this slide, and 22 of those need no adapter plate. This slide uses SIG P365 optic cut (RMSc pattern).

No plate neededPlate neededDoesn’t fit

Mount systemSIG P365 optic cut (RMSc pattern)
Optics that fit22 of 77
No plate needed22
Slide tappedM3 × 0.5 or M4 × 0.7, by slide

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

Screw thread trapSIG tapped early P365 optic cuts M3 × 0.5 and later ones M4 × 0.7, and sells a screw set for each. The model name doesn't tell you which slide you have; SIG's screw-set page shows both. We have found no date or serial-number rule from the maker for which thread a slide has, so there is no shortcut. To tell which yours is, turn an M3 screw in by hand only: if it catches and runs in smoothly, the slide is M3; if it wobbles and never bites, it is M4. Never put a driver on a screw that won't start by hand. Source: SIG Sauer, ROMEO-X M4 screw set ↗; SIG Sauer, ROMEO-X M3 & M4 screw kit ↗; SIG Sauer, ROMEOZero operator's manual (REV10) ↗; SIG Sauer, ROMEO-X enclosed Compact and Pro operator's manual (REV10) ↗; SIG Sauer, ROMEOZero-ELITE operator's manual (REV00) ↗.

Cheapest ways to mount it

Cheapest overall, and with no plate$60–150SIG Sauer ROMEOZerodirect — no adapterBuild sheet
Cheapest enclosed emitter$300–450Holosun EPS-COREdirect — no adapterBuild sheet
Same slide cutThe SIG Sauer P365 Optics Ready, SIG Sauer P365XL, SIG Sauer P365-XMACRO / XMACRO Comp, SIG Sauer P365-AXG Legion, SIG Sauer P365-380 and SIG Sauer P365 Fuse share this slide's optic cut (SIG P365 optic cut (RMSc pattern)), 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 opticMilled for the Shield RMSc pattern. No plate is needed. Holosun K optics bolt on directly as well. P365 SIG-LOC slides are a different cut, listed separately.

Every optic, and how it mounts

ItemFootprintHow it mountsCost to mount
Direct — 15
Crimson Trace CTS-1550Build sheetShield RMScdirect — no adapter$150–300
Holosun EPS-CORE EnclosedBuild sheetShield RMScdirect — no adapter$300–450
JP Enterprises JPointBuild sheetShield RMScdirect — no adapter$150–300
Olight Osight SBuild sheetShield RMScdirect — no adapter$60–150
Primary Arms Classic 21 mm MicroBuild sheetShield RMScdirect — no adapter$60–150
Riton 3 TACTIX MPRD 2Build sheetShield RMScdirect — no adapter$150–300
Shield Sights RMS2Build sheetShield RMScdirect — no adapter$150–300
Shield Sights RMScBuild sheetShield RMScdirect — no adapter$150–300
SIG Sauer ROMEO-X CompactBuild sheetShield RMScdirect — no adapter$150–300
SIG Sauer ROMEOZeroBuild sheetShield RMScdirect — no adapter$60–150
SIG Sauer ROMEOZero EliteBuild sheetShield RMScdirect — no adapter$150–300
Springfield Armory Hex WaspBuild sheetShield RMScdirect — no adapter$150–300
Swampfox Sentinel IIBuild sheetShield RMScdirect — no adapter$60–150
Viridian RFX35Build sheetShield RMScdirect — no adapter$60–150
Vortex Defender-CCWBuild sheetShield RMScdirect — no adapter$150–300
Direct (cross-fit) — 7
Holosun 407K X2Build sheetHolosun Kdirect — no adapter$150–300
Holosun 507K X2Build sheetHolosun Kdirect — no adapter$300–450
Holosun 507K X3 / 407K X3Build sheetHolosun Kdirect — no adapter$300–450
Holosun EPS EnclosedBuild sheetHolosun Kdirect — no adapter$300–450
Holosun EPS Carry EnclosedBuild sheetHolosun Kdirect — no adapter$300–450
Holosun SCS Carry EnclosedBuild sheetHolosun Kdirect — no adapter$300–450
Olight Osight KBuild sheetHolosun Kdirect — no adapter$60–150
No fit — 55
ADE Delta ProTrijicon RMRno known route—
ADE NUWAcc ProTrijicon RMRccno known route—
Aimpoint ACRO C-2 EnclosedAimpoint ACROno known route—
Aimpoint ACRO P-1 EnclosedAimpoint ACROno known route—
Aimpoint ACRO P-2 EnclosedAimpoint ACROno known route—
Aimpoint COA EnclosedAimpoint COA / A-Cutno known route—
Aimpoint Micro T-2 EnclosedAimpoint Microno known route—
Ameriglo HavenTrijicon RMRno known route—
Burris FastFire 3Docter / Noblexno known route—
Burris FastFire 4Docter / Noblexno known route—
Bushnell RXS-100Leupold DeltaPoint Prono known route—
C-More RTS2C-More RTS2 / STS2no known route—
C-More STS2C-More RTS2 / STS2no known route—
C&H Precision CompTrijicon RMRno known route—
Cyelee Cat / WolfTrijicon RMRno known route—
EOTECH EFLX MiniLeupold DeltaPoint Prono known route—
Holosun 407C X2Trijicon RMRno known route—
Holosun 407COMPTrijicon RMRno known route—
Holosun 507-PromaxTrijicon RMRno known route—
Holosun 507C X2Trijicon RMRno known route—
Holosun 507C X3 / 407C X3Trijicon RMRno known route—
Holosun 507COMPTrijicon RMRno known route—
Holosun 508T X2Trijicon RMRno known route—
Holosun 509T EnclosedHolosun 509Tno known route—
Holosun SCS 320 EnclosedHolosun SCS (320)no known route—
Holosun SCS MOS EnclosedHolosun SCS (MOS)no known route—
Leapers UTG OP3 MicroDocter / Noblexno known route—
Leupold DeltaPoint ProLeupold DeltaPoint Prono known route—
Lucid Optics E7 EnclosedAimpoint ACROno known route—
Meopta MeoSight IVDocter / Noblexno known route—
Meprolight MPO-DFTrijicon RMRno known route—
Noblex Sight III / Docter Sight CDocter / Noblexno known route—
Riton 3 TACTIX PRDTrijicon RMRno known route—
SIG Sauer ROMEO-X EnclosedSIG-LOCno known route—
SIG Sauer ROMEO-X ProLeupold DeltaPoint Prono known route—
SIG Sauer ROMEO-X SIG-LOC Compact EnclosedSIG-LOCno known route—
SIG Sauer ROMEO-X SIG-LOC Pro EnclosedSIG-LOC PROno known route—
SIG Sauer ROMEO1PROSIG Romeo1Prono known route—
SIG Sauer ROMEO2 EnclosedSIG Romeo2no known route—
Sightmark Mini Shot A-SpecDocter / Noblexno known route—
Springfield Armory Hex DragonflyDocter / Noblexno known route—
Steiner MPS EnclosedAimpoint ACROno known route—
Swampfox Justice IITrijicon RMRno known route—
Swampfox Liberty IITrijicon RMRno known route—
Trijicon RCR EnclosedTrijicon RCRno known route—
Trijicon RMR HDTrijicon RMRno known route—
Trijicon RMR Type 2Trijicon RMRno known route—
Trijicon RMRccTrijicon RMRccno known route—
Trijicon SROTrijicon RMRno known route—
Viridian RFX45 EnclosedAimpoint ACROno known route—
Vortex Defender-SLLeupold DeltaPoint Prono known route—
Vortex Defender-STLeupold DeltaPoint Prono known route—
Vortex Defender-XLLeupold DeltaPoint Prono known route—
Vortex VenomDocter / Noblexno known route—
Vortex ViperDocter / Noblexno known route—
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

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