The 407K and 507K share one adapter; the real question is your slide

Holosun's 407K and 507K are different optics, but they share the same mounting footprint. That means the same Holosun K-series adapter plate can serve either sight. The decision is not which adapter fits 407K versus 507K; it is whether your Glock's slide has the MOS mounting system and is not one of the excluded models.

The Holosun 407K/507K Glock adapter sold by Precision Optique is made for Glock pistols with the MOS system, except the 43X and 48. If you own a 43X or 48, this adapter is not the right choice according to the catalog. For other MOS Glocks, the adapter provides a platform for mounting a 407K or 507K.

What actually differs between a 407K and 507K setup

The adapter interface is the same for both sights. Any difference in your build comes from the optic you choose, not from the plate.

  • Footprint: The Holosun 407K and 507K use the same K-series footprint, so one adapter covers both. The catalog confirms compatibility with only the 407K and 507K models.
  • Slide compatibility: The adapter fits Glock MOS models except the 43X and 48. This is the same for either optic, so check your model first.
  • Optic features: The supplied catalog does not list reticle, brightness, or battery differences between the 407K and 507K. Choose between the sights based on information from Holosun, not on this adapter's listing.

Check these three points before you order

  • Your Glock must have the MOS system: The adapter is designed for Glock pistols equipped with the MOS mounting system. A non-MOS slide is not supported by the catalog description.
  • The 43X and 48 are excluded: Even if those models have MOS, the catalog explicitly excludes the 43X and 48 from this adapter's compatibility.
  • Your optic must be a 407K or 507K: The adapter is listed as compatible only with the Holosun 407K and 507K. Do not assume it fits other Holosun K-series or full-size models without confirming the footprint.

Catalog evidence for the Holosun 407K/507K Glock adapter

  • Adaptateur Holosun 407K/507K pour Glock: Compatible with Glock MOS models except the 43X and 48. This is the primary fit check: if your Glock is a 43X or 48, the adapter is not intended for your slide.

    Adaptateur Holosun 407K/507K pour Glock

    Adaptateur Holosun 407K/507K pour Glock

  • Adaptateur Holosun 407K/507K pour Glock: Compatible only with Holosun 407K and 507K models. Confirms the shared K-series footprint and rules out other optics unless separately verified.

  • Adaptateur Holosun 407K/507K pour Glock: Made from duraluminium and weighs 30 g. Gives a sense of the material and added mass, though the catalog does not state how this affects felt recoil or balance.

  • Adaptateur Holosun 407K/507K pour Glock: Operating temperature range: -30°C to 60°C; storage range: -40°C to 70°C. Useful if you shoot or store your pistol in extreme cold or heat, though the adapter itself has no electronics.

What the catalog does not tell you about installation

The supplied information says the adapter is designed to be easy to install and use, but it does not include step-by-step instructions, required torque values, or screw sizes. It also does not confirm whether you reuse the Glock MOS plate screws or need different hardware. Those details matter for a secure mount, so check the adapter's packaging or contact Precision Optique before installation rather than guessing.

The catalog also does not state whether the adapter changes the sight height enough to affect co-witnessing with factory iron sights. If that matters for your setup, verify it with the manufacturer or a qualified gunsmith.

Bottom line for 407K and 507K owners

If you have a Glock MOS model other than the 43X or 48 and plan to mount a Holosun 407K or 507K, this adapter is the catalog-supported choice for either sight. If you have a 43X or 48, or a non-MOS Glock, look for a different mounting solution. The 407K versus 507K decision comes down to the optic's features, not the plate.