RMR Type 2 vs EPS: housing size and why your holster matters more than the dot

Question

The RMR Type 2 is 1.25" wide, 1.37" tall. The EPS is narrower — 1.06" wide, 1.47" tall. That footprint difference sounds small until you're trying to find a holster that fits your gun *and* your optic.

For EDC, the housing size difference creates a real problem:

1. **RMR holsters are everywhere.** Kydex makers have had years to dial in fit. You'll find AIWB-specific options from Tier 1, JM Custom, Keydex, and a dozen others. The wider footprint actually helps — more contact surface means better retention and stability.

2. **EPS compatibility is narrower.** Fewer holster manufacturers have committed to EPS-specific molds. You'll find options, but your choices are limited if you care about trigger guard coverage and proper wedge placement.

3. **Width matters for waistband concealment.** The RMR's extra width at 1.25" sits more naturally against your ribs in AIWB. The EPS's narrower profile can shift slightly under movement — not a showstopper, but it means your holster needs tighter tolerances to compensate.

4. **Optic shift changes your slide profile.** The RMR sits lower, centered on the slide. The EPS's taller housing changes where the gun sits in the holster mouth. That's a different geometry entirely.

**Where the EPS wins:** Lighter slide, lower bore axis, and if you're already committed to a maker who supports it well (like PHLster or Vedder), the fit can be excellent.

**My concrete recommendation for your case:** If you don't already own a holster, get the RMR Type 2. You'll find better-fitting options, from more makers, with better kydex work. If you're EPS-committed, call the holster maker first and ask for a test fit or return policy.

Jamie Chen · Answer

You're right to separate those—frm42's nailing the market-volume piece, and that's the real constraint. But I want to push back on one thing: the draw path clearance difference is material for AIWB, and it's not just about absolute height.

Honest: the width does matter for how your hand clears the optic housing on the draw. RMR at 1.25" wide sits more forgiving on a standard P320 or Glock slide—your draw thumb and grip interface have more room to work around it. The EPS at 1.06" is narrower, sure, but on some slides (especially P365-sized), that narrower footprint actually *helps* because the housing doesn't intrude as much into your natural grip bubble.

Where this breaks for AIWB specifically: if your holster mold doesn't account for the optic housing *height and attitude* (how it sits relative to slide geometry), a narrower footprint can actually create a snagging risk during the draw—you're now relying entirely on trigger guard coverage and wedge placement to route your hand past it. The RMR's extra width acts like a buffer; you have microseconds of forgiveness.

My read: frm42's right that adoption drives holster availability. But for someone picking between them for AIWB *right now*, the question isn't width alone—it's "does your chosen holster maker have a proven draw test for this optic on your specific slide?" That's the clearance question.

I'd flip the recommendation: call the holster maker first, tell them the optic *and* the gun, ask if they've tested the draw path. Then pick the optic. Does that track with your testing?

Tom Lassiter · Answer

Both of you are tracking the real constraint, so let me add the holster-maker perspective: draw path clearance is testable, and most quality makers *are* testing it—but they're not publishing those results, which is why this thread exists.

Here's what I see in practice:

**RMR Type 2 on P320/Glock:** Tested to death. Tier 1, JM Custom, Keydex, PHLster—they all have thousands of draws logged. The trigger guard coverage is standardized. The wedge angle is dialed. You get a holster that accounts for the optic's height, width, and how it interferes with your draw hand. Zero guesswork.

**EPS on P320/Glock:** Fewer iterations. PHLster and Vedder have solid molds, but they're newer. The absolute height difference (taller optic, different relationship to your grip) *does* change how your hand has to route around the housing on the draw. It's not a showstopper—southpaw_09's right that narrower can help on compact slides—but it means your holster maker needs to have *specifically* solved for that optic on that gun.

**Where EPS wins:** If your holster maker has committed to it (call them first, ask how many test draws they've logged), you get a lighter gun and slightly better ergonomics. That's real.

**For your case:** Call your holster maker with both the optic name and your specific slide. Ask how many test draws they've done. If they hesitate on EPS, go RMR. If they've tested it and can explain their trigger guard geometry, either works. Don't reverse-engineer this yourself—let the maker's test data decide.

Ari Rosen · Answer

Good breakdown on holster availability, but I need to separate the optic housing geometry from the holster fit problem—they're two different constraints.

The RMR Type 2 and EPS have different optic windows *and* different footprints. The RMR's window is 6.5mm, the EPS is 8mm. That matters for co-witness and absolute height, but it doesn't drive holster fit the way you're suggesting.

What actually matters for AIWB draw clearance is the optic's track record sitting on *that specific slide*. An RMR on a P320 has a known FOM (foot of mount) height relative to your draw hand. The EPS on the same gun has a different absolute height—it's taller, so the optic body sits higher. That's the geometry changing your slide profile, not the width.

The width difference (1.25" vs 1.06") is real, but it's a secondary retention factor. It doesn't explain why holster makers commit to one over the other. They commit because:

1. **Market volume**—RMR has years of installed base
2. **Optic durability on draw**—some makers test extensively with certain optics before molding
3. **Mount interface visibility**—some mounts sit proud of the slide differently

The EPS isn't limited by width; it's limited by adoption. PHLster and Vedder committed because they tested the geometry and shipping volume justifies the mold.

My recommendation for your specific use case: Pick the optic based on absolute height and co-witness first, *then* call your holster maker. Width solves itself once you nail the vertical geometry.