The SIG Sauer P365 family; P365, P365X, P365XL, P365 AXG Legion, P365 XMacro, and variants; uses SIG’s XSERIES optic cut, accepting the Romeo Zero footprint and RMSc/K-series optics via adapter.
Holosun K-series optics (507K, 407K, EPS Carry) fit via a thin adapter plate. The Holosun SCS Carry mounts to the P365’s optic cut without any plate, providing solar-primary enclosed operation.
The P365 family’s primary role is daily concealed carry, which defines the optic priorities: lightest possible weight, always-ready activation, and enclosed emitter protection for IWB and AIWB use. Holosun’s K-series addresses all three: 0.7 oz for the 507K X2, solar + shake-awake for always-ready, and EPS Carry for enclosed protection.
Best Holosun Optics for SIG P365
- Holosun 507K X2 – Best Overall
- Holosun EPS Carry – Best Enclosed
- Holosun SCS Carry – Best Solar Direct
- Holosun 407K X2 – Best Budget
- Holosun 507K-GR X2 – Best Green
- Holosun EPS Carry GR – Best Green Enclosed
- Holosun 507K (standard) – Best Value Step-Up
Best Holosun Optics for SIG P365: Comparison Table
Holosun 507K X2 |
Holosun EPS Carry |
Holosun SCS Carry |
Holosun 407K X2 |
Holosun 507K-GR X2 |
Holosun EPS Carry GR |
Holosun 507K (standard) |
|
|---|---|---|---|---|---|---|---|
| Mount | Thin adapter | Thin adapter | Direct P365 | Thin adapter | Thin adapter | Thin adapter | Thin adapter |
| Plate | Thin adapter | Thin adapter | No | Thin adapter | Thin adapter | Thin adapter | Thin adapter |
| Emitter | Open | Enclosed | Enclosed | Open | Open | Enclosed | Open |
| Dot Color | Red | Red | Green | Red | Green | Green | Red |
| Reticle | 2 MOA + 32 MOA | 2 MOA + 32 MOA | 32 MOA + 2 MOA | 2 or 6 MOA | 2 MOA + 32 MOA | 2 MOA + 32 MOA | 2 MOA + 32 MOA |
| Solar | Yes (X2) | Yes | Yes | No | Yes (X2) | Yes | No |
| Activation | Shake-awake + solar | Shake-awake + solar | Solar always-on | Shake-awake | Shake-awake + solar | Shake-awake + solar | Shake-awake |
| Weight | ~0.7 oz | ~1.2 oz | ~1.4 oz | ~0.6 oz | ~0.7 oz | ~1.2 oz | ~0.7 oz |
| Warranty | 10-yr | 10-yr | 10-yr | 10-yr | 10-yr | 10-yr | 10-yr |
| Check Price | Check Price | Check Price | Check Price | Check Price | Check Price | Check Price | Check Price |
1. Holosun 507K X2 – Best Overall
The Holosun 507K X2 is the most used Holosun optic on the P365 family across all variants. The K-series compact format is proportionate to the P365’s short slide, and the X2 generation’s solar failsafe addresses the most critical reliability concern for a daily carry optic. At 0.7 oz via a thin adapter, the 507K X2 adds nothing to the P365’s 17.8 oz loaded carry weight.
The multi-reticle is the defining feature advantage. For a P365 daily carry pistol, the 32 MOA circle provides the fast acquisition that defensive draw situations demand; under stress, finding a large circle on the target is more reliable than finding a 2 MOA dot with precise alignment.
The 2 MOA dot is available for deliberate range work and training. Solar failsafe maintains the battery charge during outdoor daily carry, and shake-awake ensures the optic is live within 0.3 seconds of the pistol leaving the holster.
The 507K X2 is SIG’s own recommendation; they list the 507K on their website as the recommended optic for P365 platforms.
This factory endorsement, combined with extensive community documentation of the 507K on every P365 variant, makes it the most confident recommendation in the entire P365 Holosun category.
The 507K X2 is the complete Holosun solution for compact carry platforms; all core reliability features in the K footprint designed for slimline pistols.
Pros
- SIG-recommended optic for P365 platforms on their own website
- Multi-reticle: 32 MOA circle for defensive speed + 2 MOA dot
- Solar failsafe on X2; always powered outdoors
- 0.7 oz minimal weight on P365 carry pistol
- Most documented P365 Holosun in community reports
- Holosun 10-year warranty
Cons
- Open emitter; thin K-series adapter plate required; CR1632 battery
2. Holosun EPS Carry – Best Enclosed
The EPS Carry provides enclosed emitter protection in the K-series compact format for P365 daily carry.
For P365 owners who carry AIWB in climates where daily sweat is a reality, the sealed housing prevents the moisture and lint accumulation that affects open emitters over months of daily wear. The feature set matches the 507K X2: solar failsafe, shake-awake, multi-reticle.
P365 owners cite the EPS Carry for deep concealment carry where the pistol faces more debris exposure than duty or open carry configurations.
The P365’s role as a primary deep concealment carry gun makes enclosed emitter protection more relevant here than on larger-format carry pistols where the optic is better protected by the holster.
At 1.2 oz, the EPS Carry is 0.5 oz heavier than the 507K X2. On a P365 carry pistol where the total loaded weight is already minimal, this difference is imperceptible in carry. The thin adapter plate installation is identical to the 507K X2.
The EPS Carry brings sealed emitter protection to compact carry platforms for shooters who prioritize environmental reliability above all other features.
Pros
- Enclosed emitter for deep concealment P365 carry
- Solar failsafe + shake-awake matching 507K X2
- Multi-reticle in enclosed housing
- Best for AIWB in warm/humid climates
- Holosun 10-year warranty
Cons
- 1.2 oz vs 0.7 oz for open 507K X2; thin adapter plate still required
3. Holosun SCS Carry – Best Solar Direct
The SCS Carry mounts to the P365’s optic cut without any thin adapter plate; the cleanest Holosun installation available on the P365 family. Solar-primary operation provides permanent battery charge during any ambient light condition.
Enclosed green emitter adds debris protection. For P365 carry owners who want zero maintenance from their optic, the SCS Carry delivers it.
The direct-mount advantage eliminates the thin adapter plate’s role as an intermediary between the optic base and the slide surface.
or a pistol used for daily carry rather than high-round-count training, this difference is about simplicity and security rather than practical performance.
SIG endorses the SCS Carry on their P365 product pages alongside the 507K; both are recommended options for the P365 family. The SCS Carry’s solar-primary, enclosed, direct-mount combination is the most maintenance-free P365 Holosun configuration.
The SCS Carry’s solar-primary design provides the most maintenance-free carry configuration available in the Holosun compact lineup.
Pros
- Direct mount on P365 optic cut; no thin adapter plate
- Solar always-on: immune to battery depletion
- Enclosed green emitter for carry debris protection
- SIG-endorsed for P365 platforms
- Holosun 10-year warranty
Cons
- Green reticle only; premium price; heavier at 1.4 oz
4. Holosun 407K X2 – Best Budget
The 407K X2 at $130–150 is the entry point into quality Holosun carry use on the P365. Shake-awake and 50,000-hour battery without the multi-reticle and solar premium of the 507K X2. The K-series thin adapter installation is the same. For P365 owners on a budget who want reliable Holosun carry performance, the 407K X2 provides it.
The 2 MOA or 6 MOA dot options let buyers choose based on their preference: 2 MOA for precision-focused carry, 6 MOA for maximum close-range speed. The 10-year warranty provides full coverage at budget pricing.
The 407K X2 provides solar failsafe and shake-awake at the lowest price point in the Holosun K-series lineup for budget-focused compact carry builds.
Pros
- Sub-$150; most affordable K-series Holosun for P365
- Shake-awake
- 50,000-hour battery
- Holosun 10-year warranty
Cons
- No solar; single dot; thin adapter plate
5. Holosun 507K-GR X2 – Best Green
Green multi-reticle for P365 astigmatism users. SIG-recommended alongside the red 507K for the P365 family. Feature-identical to 507K X2 in green.
The P365 is often carried in a pocket or appendix position, where the pistol is close to body heat and lighting conditions vary throughout the day.
For astigmatism sufferers who find red emitters distorted in these conditions, the green 507K-GR X2 provides the clearest possible reticle appearance.
Pros
- Green for astigmatism clarity on P365
- Full 507K X2 feature set
- SIG-recognized for P365 platforms
- Holosun 10-year warranty
Cons
- Premium over red; open emitter; thin adapter plate
6. Holosun EPS Carry GR – Best Green Enclosed
Green enclosed emitter for P365 astigmatism carry users. Combines both Holosun astigmatism solutions in one optic for P365 deep concealment.
For P365 owners with astigmatism who carry in demanding environments where enclosed protection is important, the EPS Carry GR is the specific answer. No other single Holosun optic on this list provides both green emitter clarity and enclosed carry protection.
The EPS Carry brings sealed emitter protection to compact carry platforms for shooters who prioritize environmental reliability above all other features.
The green enclosed EPS Carry combines sealed housing and green wavelength for the most protected astigmatism-friendly compact carry option.
Pros
- Green + enclosed: astigmatism + carry protection
- Solar + shake-awake + multi-reticle
- Best for astigmatism deep concealment P365 carry
- Holosun 10-year warranty
Cons
- Green only; 1.2 oz; thin adapter plate
7. Holosun 507K (Standard, No X2) – Best Value Step-Up
The non-X2 507K provides the multi-reticle and shake-awake of the current lineup without the X2 generation’s solar failsafe, at a lower price point when found on sale or clearance.
For P365 carry owners who want multi-reticle and shake-awake but don’t want to pay the X2 solar premium, the standard 507K is the value option.
Solar failsafe is genuinely important for outdoor carry, and the X2 upgrade is worth it for most carry applications. But for indoor carry or budget-constrained buyers, the standard 507K provides the core features at a lower price.
Pros
- Multi-reticle + shake-awake at a lower price than the 507K X2
- 50,000-hour battery
- K-series for P365
- Holosun 10-year warranty
Cons
- No solar failsafe; thin adapter plate; being superseded by X2 generation
Holosun Lineup Guide for Compact and Sub-Compact Carry
K-Series vs Standard Holosun for Compact Platforms
For compact and sub-compact pistols using Shield RMSc or K-series footprints, the Holosun K-series (507K X2, 407K X2, EPS Carry, SCS Carry) are the correct choices.
Standard Holosun models (507C X2, 509T X2) use the larger RMR footprint and will not fit compact carry cuts without a separate adapter.
507K X2 as the Complete Compact Solution
The Holosun 507K X2 provides the complete feature set: solar failsafe, shake awake, multi-reticle system, 50,000-hour battery life, in the compact K footprint designed for slim carry pistols.
It is the default Holosun recommendation for any compact carry platform with Shield RMSc or K-series compatibility.
EPS Carry for Maximum Environmental Protection
The Holosun EPS Carry brings the enclosed emitter advantage of the 509T X2 to a compact footprint.
For carry shooters who prioritize sealed emitter protection over minimizing optic bulk, the EPS Carry is the appropriate compact choice.
Solar Failsafe on Every K-Series Model
All current Holosun K-series models include solar failsafe.
This means even the budget 407K X2 provides carry-grade battery management; the solar cell charges the optic in ambient light, eliminating battery anxiety for any pistol carried in normal lighting conditions.
Frequently Asked Questions
Does SIG recommend any specific Holosun for the P365?
Yes; SIG Sauer’s website lists the Holosun 507K and SCS Carry as recommended optics for P365 platforms. Both are available through the SIG accessories section.
Does the thin adapter plate affect the P365’s optic height?
Minimally; the thin K-series adapter adds 1–2mm of height over the direct-fit RMSc optics. This is imperceptible in carry and doesn’t affect holster fit for most P365 optic-compatible holsters.
Final Verdict
For the SIG P365 family: 507K X2 is the SIG-recommended community standard; multi-reticle, solar failsafe, 0.7 oz. Enclosed carry: EPS Carry. Direct-mount solar: SCS Carry; also SIG-endorsed. Budget: 407K X2. Astigmatism: 507K-GR X2. Green enclosed astigmatism: EPS Carry GR.