Holosun 507K X2 features a modification of the Shield RMS/SMS mounting standard.
Dimensions of the Holosun 507K X2 footprint
All the distances are in millimeters.
Looking for suitable mounting solutions?
A photo of the Holosun 507K X2 footprint
Click here to find out more about the modification of the Shield standard on the Holosun 507K X2.

is an optics enthusiast who writes articles and reviews in the field of binoculars, riflescopes, NV optics etc. Currently, he is a member of the Optics Trade team.
Summary

Article Name
Holosun 507K X2 Footprint
Description
Holosun 507K X2 features a modification of the Shield RMS/SMS mounting standard. Here, you can see the dimensions and the photo of the footprint.
Author
Andraž Gradišnik
Publisher Name
Optics Trade
Publisher Logo

Is there a plate for the 507k x2 to go on my Rival. So I don’t have to modify?
Sadly, I do not know of such a plate.
EGW makes a line of red dot mounts for various footprints. It utilizes existing rear dovetail for fitting sight. If you’re talking about the nerf gun, just superglue an ultra cheap RD sight to the unit. 🙂