Check your slide before you buy: MOS or MOSK?
Some newer Glock Slimline pistols use an updated MOS-K optic cut. Look at the item number sticker on your pistol case. If the item number includes MOSK near the end, Glock says the slide accepts Holosun K footprint optics without an adapter plate, so you do not need this plate. If it shows MOS without the K, this plate is what lets a Holosun 407K or 507K mount on your slide. How to tell MOS from MOSK
30-Day Perfect Fit Guarantee — If the adapter plate does not fit your Glock 43X/48 MOS perfectly, return it for a full refund. No questions asked.
- Wide Compatibility: Designed for Glock 43X MOS / 48 MOS and Springfield Hellcat OSP / Hellcat Pro OSP. Mounts Holosun 407K and 507K optics, including the X2 and green-dot versions.
- Enhanced Stability: Reinforced impact posts help keep your optic securely in place under recoil.
- Easy Installation: One-piece design that installs with the included mounting screws and screwdriver.
- Ultra-Thin Profile: Just 1.4 mm (0.055 inch) thick per our engineering drawing, which keeps the optic low. Co-witness depends on your iron sights.
- Precision-Machined Titanium: Machined from solid Ti-6Al-4V titanium with a black PVD coating.
Watch: Installation Guide
See how the AltitudeCraft AC311 adapter plate installs on a Glock 43X MOS:
How Does AltitudeCraft Compare?
| Feature | AltitudeCraft AC311 | C&H Precision V4 | Generic Plates |
|---|---|---|---|
| Price | $25.99 | $51.99 | $15-20 |
| Material | Titanium | Aluminum | Aluminum / Steel |
| Thickness | 1.4 mm (0.055 inch) | Not stated | Varies |
| Recoil Posts | Reinforced | Standard | Basic |
| Finish | Black PVD coating | Anodized | Varies |
| Fit Guarantee | 30-Day | Not stated | None |
| Hardware Included | 4 screws + screwdriver | Yes | Varies |
Does It Fit Your Setup?
Compatible Firearms:
- Glock 43X MOS
- Glock 48 MOS
- Springfield Hellcat OSP
- Springfield Hellcat Pro OSP
NOT Compatible:
- Glock 43X (non-MOS) — requires slide milling
- Glock 19 MOS — different footprint
- Glock 17 MOS — different footprint
Compatible Optics:
- Holosun HS407K / HE407K / HS407K X2 / HE407K-GR X2
- Holosun HS507K / HE507K / HS507K X2 / HE507K-GR X2
Other optics are not listed until we have confirmed the fit.
Not sure which red dot to pair with this plate? Read our in-depth guide: Best Red Dots for Glock 43X MOS — Direct Fit vs Adapter Plate Options
Frequently Asked Questions
What Glock models does this adapter plate fit?
It is designed for the Glock 43X MOS and Glock 48 MOS, and also for the Springfield Hellcat OSP and Hellcat Pro OSP. It does not fit non-MOS slides or the Glock 17/19 MOS.
Which red dot sights are compatible?
It mounts the Holosun 407K and 507K families, including the X2 and green-dot versions (HS407K, HE407K, HS407K X2, HE407K-GR X2, HS507K, HE507K, HS507K X2, HE507K-GR X2). We only list optics we have confirmed.
What material is the adapter plate made from?
It is precision-machined from solid Ti-6Al-4V titanium and finished with a black PVD coating.
Will I achieve co-witness with my iron sights?
The plate is 1.4 mm (0.055 inch) thick per our engineering drawing, which keeps the optic low. Whether you can co-witness, and whether it is absolute or lower-1/3, depends on your optic and your iron sights.
What hardware is included and how difficult is installation?
Each set includes the adapter plate, 4 mounting screws and a screwdriver. Watch our installation video.
What is the 30-Day Fit Guarantee?
If the adapter plate does not fit your Glock 43X/48 MOS perfectly, return it within 30 days for a full refund. No questions asked. We stand behind our precision machining.
How does this compare to the C&H Precision plate?
The AltitudeCraft AC311 is machined from titanium, while C&H lists 6061 aluminum for its plate. The AC311 comes with a 30-Day Fit Guarantee and costs about half as much ($25.99 vs $51.99, C&H list price checked October 2026).
Customer Reviews
Based on 5 reviews
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A
Perfect fit
A
Fit is great with a low profile, plate is very light , no issues with mounting my optic, would highly recommend
A
Perfect Fit. Looks well made.
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Perfect fit! Thanks a million!
J
Ordered this adapter plate extremely thin super sturdy. Works perfectly on my GEN 5 GL 43X MOS can barely see it. Its so flushed with my 43X MOS slide and my 407K X2 you don't even notice it. Makes it fir nice sleek look and feel, great tactical looking aesthetics. It looks good! Would shoot you a pic but i don't see how on this review site.
