GPO Spectra Red Dot features a modified Aimpoint Micro mounting standard. There is a protruding part underneath the illumination adjustment knob, which is why adapters designed for the Aimpoint Micro mounting standard cannot be combined with it.
Dimensions of the GPO Spectra Red Dot footprint
All the distances are in millimeters.
A photo of the GPO Spectra Red Dot footprint
Click here to find out more about the modification of the Aimpoint standard on GPO Spectra Red Dot.